“So the Trump official, Tom Homan — we all know who he is he said, quote, I’m quoting him: ‘If he doesn’t come through, I’ll be in his office up his butt.’ Sorry, Chairman. Saying, ‘where the hell is the agreement we came to?’ End of quote. You’re accusing the Trump administration for lying. Did they lie? What agreement — they’re lying, then.” “Mr. Homan and I both agree we would fight dangerous criminals. And we’ve never had any conversation about my case.”

“Now, Mr. Mayor, we have a right to know if the Trump administration has actually coerced you into agreeing to anything. And, Mayor Adams, I also want to be very clear. Are you selling out New Yorkers to save yourself from prosecution?” “There’s no deal. No quid pro quo. And I did nothing wrong. And anything dealing with this case out of deference to Judge Ho, who’s now addressing it, I’m going to refer to his actions.” “Now, I personally agree with the majority of New Yorkers and think, Mr. Mayor, that you should resign. You should do the right thing. You should step down and resign today. And with that, I yield back.”

“The city of Chicago is a beautiful place. We also have 20 percent of the world’s fresh water right in our front yard. Our restaurants are amazing. In fact, everything that is dope about America comes from Chicago.” “A Republican named Lincoln was nominated for president in Chicago, and a Democrat named Obama called Chicago home, too. As the city of big shoulders, the heart of the heartland, the home to the world’s best pizza, and we’re not going to take any slander from Donald Trump or anyone else lying down, is that right?” “That is correct.”

Let’s talk about Tom Homan. Shame on him for lying about my city, for having the nerve to insult our police commissioner, who has overseen the safest Boston’s been in anyone’s lifetime. Bring him here under oath, and let’s ask him some questions. I am here to make sure that the city of Boston is safe. Others may want to bring hell. We are here to bring peace to cities everywhere.

House Republicans on Wednesday accused the Democratic mayors of New York, Denver, Boston and Chicago of harboring criminal immigrants, hammering them for refusing to fully cooperate with President Trump’s enforcement efforts and suggesting they had put their residents in danger. The mayors defended their policies and their cities’ efforts to house and feed migrants who were bused to their communities by Republican governors.

Republicans on the House Oversight Committee stepped up their confrontational tone in the second half of the hearing, with Representative Nancy Mace, Republican of South Carolina, asking questions like whether the mayors hated President Trump more than they loved their country, demanding yes or no answers. The Republicans cited some specific cases where people had been attacked or killed by undocumented migrants, suggesting cities’ immigration polices had contributed to those crimes.

The mayors defended their public safety records, saying they complied with all federal and state immigration laws, and pointing out that crime rates in their cities had dropped in recent years, in spite of President Trump’s claims that migrants make cities unsafe. Several times, the mayors turned Republicans’ accusations back on them, urging them to focus on the economy, pass immigration reform, strengthen gun laws and oppose other Trump administration policies they described as harmful.

“If you wanted to make us safe, pass gun reforms,” Mayor Michelle Wu of Boston said. “Stop cutting Medicaid. Stop cutting cancer research. Stop cutting funds for veterans.”

The committee: Republicans on the House Committee on Oversight and Government Reform echoed Mr. Trump’s attacks on city leaders during the hearing. The committee, which is stocked with Republican firebrands including Jim Jordan, Lauren Boebert and Marjorie Taylor Greene, promoted the mayors’ appearance with a sizzle reel set to dramatic music and video clips of tent cities, criminals with guns and the Declaration of Independence up in flames. Read more about the committee and its members.

What’s at stake: Mr. Trump has threatened to withhold federal money from jurisdictions he deems uncooperative with his immigration efforts, and he recently filed a lawsuit accusing leaders in Chicago of thwarting his policies. Democrats have long championed policies that limit local law enforcement cooperation with immigration agents as a way to create safe and welcoming communities. Here’s what to know about sanctuary cities.

Seeking a viral moment: Republicans repeatedly sought to trap the mayors into the kind of stumbles that derailed the presidents of Harvard, Columbia and the University of Pennsylvania, who lost their jobs after testifying before Congress about campus antisemitism. Here’s why the mayors showed up to testify.

Adams under attack: Mayor Eric Adams of New York was largely spared Republican scrutiny of the city’s immigration policy. But he was questioned by Democrats about accusations that he had engaged in a quid pro quo with the Trump administration, seeking an end to federal corruption charges against him in exchange for help on immigration. Representative Robert Garcia, Democrat of California, called on Mr. Adams to resign; the mayor said he had done nothing wrong. Here’s what to know about his appearance.

One of the most mentioned figures at this hearing is no longer in office: former President Biden. His name has come up roughly 30 times, mostly from Republicans blaming him for failing to secure the border. One Republican pointedly asked Mayor Michelle Wu of Boston whether she supported the Biden-Harris administration and whether she believed they took border security seriously.

Wu replied, “I think Washington failed on immigration and continues to do so.”

Throughout the hearing, Democrats have tried to explain the details of immigration enforcement policy and what exactly cities and states are required to do under law. Representative Dave Min of California, a Democrat, argued that if cities were deputized to help enforce federal immigration laws, they would have to divert resources away from other priorities, such as investigating crimes and apprehending violent criminals.

“There is no place in America, not one, that actually provides sanctuary from federal law,” Min said. “The real issue here is whether state and local governments should spend scarce taxpayer dollars to help the federal government enforce its immigration priorities.”

Representative Alexandria Ocasio-Cortez of New York, a fierce critic of Mayor Eric Adams, asked him several questions about his lawyers’ meeting with Justice Department officials, but Adams dodged her questions. She asked if he wanted to plead the fifth. He said he would not discuss his conversations with his lawyer.

Nearly five hours into the hearing, Mayor Eric Adams appears to be growing fatigued by questions about whether he made a deal with the Trump administration to have his corruption case dismissed.

He told Representative Jasmine Crockett, Democrat of Texas: “It appears as though we’re asking the same questions over and over and over again. My comments are not going to change. No quid pro quo, no agreement. I did nothing wrong.”

Mayor Eric Adams was asked about his Fox News interview with Thomas Homan, Trump’s border czar, and Homan’s comments that if Adams did not help with immigration enforcement, he would be “up his butt.” Adams said there was no quid pro quo related to his criminal case: “Mr. Homan and I both agreed we would fight dangerous criminals, and we never had any conversation about my case.”

It might seem like Eric Adams, the mayor of the largest American city, which has been most affected by the migrant crisis, would be the most visible at this hearing. But he has often taken a backseat to the other mayors.

The questioning of Adams has primarily been by Democrats who have focused on accusations of a quid pro quo with Trump officials over his federal corruption case.

Representative Anna Paulina Luna, Republican of Florida, said that she planned to refer the four mayors — who she suggested were illegally harboring migrants — to the Department of Justice for criminal investigation. Her proposition is more posturing than a serious legal threat.

A congressional criminal referral does not, and likely cannot, require the D.O.J. to initiate a prosecution. There are several constitutional reasons for this.

Representative Nancy Mace of South Carolina has made some of the harshest attacks on the mayors so far and accused them of having “blood on your hands.” She criticized one of the responses from Mayor Brandon Johnson of Chicago and said that’s why his approval rating was low.

What had largely been a contentious but fairly routine hearing blew up after the break, with Representative Nancy Mace, Republican of South Carolina, asking the mayors to answer yes or no to questions like whether they hated President Trump more than they loved their country, or whether they loved illegal immigrants more than their cities’ residents.

Then a shouting match broke out between Representative Ayanna Pressley, Democrat of Massachusetts, and the committee chairman, James Comer of Kentucky, as Pressley tried to enter headlines critical of the Trump administration into the record.

The mayors of New York, Denver, Boston and Chicago on Wednesday rejected intense criticism from Republican lawmakers that their cities had devolved into dangerous places because of rapidly growing immigrant populations.

During a sometimes heated congressional committee hearing on Capitol Hill, Mayor Michelle Wu of Boston said that hers was “the safest major city in the nation,” pointing out that last year’s homicide rate was the lowest it had been in 70 years.

“And behind these record lows are historic highs: the most ever young people working paid summer jobs, the most pre-K seats at no cost to families, the most affordable housing built in a generation,” Ms. Wu said.

The other mayors similarly dismissed pointed questions about violent attacks purportedly committed by undocumented immigrants. In New York City, data does not support the existence of any “migrant crime wave,” as referenced last year by Edward Caban, the city’s former police commissioner. Police records there indicate that crime has not surged since Gov. Greg Abbott of Texas started busing migrants to New York in April 2022 to protest the federal government’s border policy.

New York’s mayor, Eric Adams, has made public safety a focus of his administration, and in January he laid out an ambitious plan to expand policing efforts, including by putting more officers in the city’s already heavily surveilled subway system.

At the hearing on Wednesday, Mr. Adams said that crime was down across New York City last year, “and we have now had three straight months of double-digit declines in major crimes,” while Mayor Brandon Johnson, of Chicago, and Representative Raja Krishnamoorthi pivoted away from the lawmakers’ line of interrogation and instead talked up the city’s business growth, its large airport and its pizza.

Thomas Homan, Trump’s border czar, defended Mayor Eric Adams on social media and called allegations that Adams was selling out New Yorkers to help himself avoid criminal prosecution “simply disgusting.” He said that Adams was “trying to protect New Yorkers from violent illegal aliens.”

House Republicans are eager for a public confrontation on Wednesday, when they plan to grill four Democratic mayors whose cities have policies that limit their cooperation with federal immigration enforcement.

As the mayors prepare to submit themselves to hours of questioning before the House Oversight Committee, which has 47 members and is widely known as one of the most combative on Capitol Hill, watchers might wonder: Why on earth would they agree to testify?

The group — Eric Adams of New York, Brandon Johnson of Chicago, Mike Johnston of Denver and Michelle Wu of Boston — is appearing voluntarily before the panel, which summoned them in January. But if they didn’t agree, the committee could demand their presence with a subpoena. That could lead to a drawn-out legal fight with Congress, and ultimately make it more likely that they would be forced to show up on Capitol Hill and treated as hostile witnesses.

In this case, a failure to appear would also mean ceding an opportunity to be heard on a pressing political issue that the mayors have each grappled with in their cities. Lawmakers have been known to hang nameplates over empty chairs at hearings when witnesses decline to appear, calling attention to the absence and arguing that they must be hiding something.

Still, showing up for the session carries risks. High-profile congressional hearings provide easy opportunities for lawmakers to issue public tirades or provoke dramatic moments that allow them to drum up media attention and fund-raising.

Republicans on the House Education Committee did so in 2023 when they summoned several university presidents amid a wave of campus protests over the Israel-Hamas war to question them about antisemitism and their handling of the unrest. Their poor performances on Capitol Hill led one of them to resign within days and another within weeks while others faced heightened scrutiny.

Annie Karni contributed reporting.

The committee is taking a 20-minute break.

The mayors have repeatedly stressed that their cities follow federal immigration laws, but Republicans continue to suggest that they should be doing more to cooperate with the Trump administration’s deportation efforts.

“We’ve got a problem here when we decide there are some laws that we obey and some laws that we won’t,” said Representative Gary Palmer, Republican of Alabama, suggesting that the mayors might be guilty of obstruction of justice.

Chairman James Comer offered a surprising comment on deportation programs, saying, “I don’t think anyone’s calling for mass deportation.” One person calling for such an effort is President Trump, who has promised the “largest domestic deportation operation in American history.”

Gerry Connolly, the committee’s top Democrat, just asked to note on the record that Trump used mass deportations as a key campaign message and, in his joint address to Congress, asked to use the military to carry out mass deportations.

Mayor Eric Adams is questioned about accusations that he engaged in a quid pro quo with the Trump administration to have his federal corruption charges dropped in exchange for the mayor’s help on immigration. He says there was “no quid pro quo” and “I did nothing wrong.”

Representative Robert Garcia of California called on Adams to resign. Many Democrats in New York have also urged him to resign, including Representative Alexandria Ocasio-Cortez, who is at the hearing. Gov. Kathy Hochul of New York has said that she is concerned about the allegations against Adams but will not use her power to remove him from office.

Republican lawmakers so far have tried to make the point that the federal government has supremacy over local and state laws, and as such, the mayors should change their local policies to cooperate with federal immigration officials.

The mayors have seized opportunities to put Republicans on the defensive, challenging the idea that undocumented immigrants pose the biggest threat to their cities. “If you want to make us safer, pass gun reform, stop cutting Medicaid, stop cutting funds for veterans,” Mayor Michelle Wu said under questioning from Representative Paul Gosar, a Republican from Arizona.

Under a friendly line of questioning from a congressional Democrat from Illinois, Mayor Brandon Johnson pushed back against Republicans’ dystopian characterizations of Chicago.

Johnson and Representative Raja Krishnamoorthi talked about Chicago’s business growth, its large airport and even its pizza. Johnson loves a good municipal pep talk, and has long made a point of calling Chicago the best “freakin’ city in the world,” a phrase he trotted out again here.

Democrats on the panel, as well as the mayors, are trying to point out that the Trump administration and Congress have done little to address what voters across the country have said was their top issue: the economy.

Mayor Michelle Wu seemed eager to engage when asked about criticism from Thomas Homan, Trump’s border czar, who has vowed to bring “hell” to Boston. Ms. Wu said, “Shame on him for lying about my city — bring him here under oath, and let’s ask him some questions.”

Chairman Comer singled out Mayor Eric Adams with praise, while being far more confrontational with the other mayors. He thanked Adams for publicly stating that he would work with federal immigration authorities to target immigrants who are accused of violent crimes. Adams has said that he is against mass deportations, but he has praised the Trump administration’s efforts to close the borders.

There are 60 members who will each have five minutes to ask questions. Chairman Comer is wasting no time, cutting off mayors’ responses when they try to explain themselves beyond a simple yes or no.

It’s interesting that the opening of this hearing, which was called to criticize “sanctuary mayors,” has actually given them a national platform to passionately defend immigrants and their policies while criticizing President Trump’s deportation plans.

A congressional committee known as one of the most combative and incendiary on the Hill will take aim Wednesday at four big-city mayors, with Republicans on the panel expected to accuse the Democratic leaders of failing to cooperate with the Trump administration’s immigration enforcement efforts.

Like Republican-led hearings over campus antisemitism that helped cost some university presidents their jobs, the hearing by the House Committee on Oversight and Government Reform is an opportunity for Republicans to produce the type of viral social media moments they can use to appeal to voters concerned about crime, as well as brand themselves as champions of President Trump’s agenda.

The committee’s chairman, Representative James Comer, a Republican of Kentucky, has framed the hearing as an attempt to root out “waste, fraud and abuse,” and has suggested without evidence that Democratic leaders are improperly channeling taxpayer dollars to provide housing and medical care to people who entered the country unlawfully.

Mr. Comer has also echoed the Trump administration’s threats to slash federal funding for the cities if they didn’t change course and aid an immigration crackdown, saying in a Newsmax interview the day he announced the investigation: “If they’re going to continue to disobey the law, I think we should cut as much of their federal funding as we can cut.”

The Democratic mayors of Denver, Boston and Chicago are expected to defend their approaches to the large migrant populations in their cities, approaches that are often designed to preserve trust between immigrant communities and law enforcement, which some research has shown is effective. But they have also dealt with a significant influx of migrants in recent years, including many asylum seekers bused to their cities by Gov. Greg Abbott of Texas.

Mayor Eric Adams of New York might take a different approach. Although Democrats on the City Council have resisted weakening the city’s sanctuary laws, Mr. Adams, a former police officer, has mirrored Republican arguments that the laws can hurt public safety. The debate has also become mired in the mayor’s personal fight against corruption charges.

The mayors will have to tread carefully to avoid the kind of public backlash that the presidents of Harvard, M.I.T. and the University of Pennsylvania faced in late 2023, after they gave clinical and lawyerly answers to questions about whether students would violate their universities’ codes of conduct if they called for the genocide of Jews.

Republicans on the committee include Representative Virginia Foxx of North Carolina, who led some of the incendiary hearings with college presidents, and Representative Marjorie Taylor Greene of Georgia, one of Mr. Trump’s most full-throated supporters in Congress.

Mayor Michael Johnston of Denver will almost certainly face tough questions from Representative Lauren Boebert, Republican of Colorado. One of the panel’s most prominent firebrands, she has repeatedly attacked her state’s “sanctuary” policies in oversight hearings this week, proclaiming on social media that they prevent federal immigration agents “from being able to do their job and remove criminal aliens from our streets!”

Congressional Republicans on Wednesday are grilling the mayors of four cities that limit the amount of cooperation they provide to federal immigration agents. Places with those policies are generally known as sanctuary cities, though the specifics of their polices vary from place to place.

Hundreds of communities across the country have offered some sort of protection to undocumented migrants — a movement that began in the 1980s, when churches across the United States offered shelter to people fleeing civil war in El Salvador, and expanded during the first Trump administration.

Leaders in those communities, including police chiefs, have argued that cooperating with federal deportation efforts erodes trust between migrant communities and local law enforcement, making their neighborhoods less safe. There’s some research to back them up, though congressional Republicans have said that sanctuary policies erode public safety and put lives at risk.

Despite the widespread adoption, there is no universal definition for what constitutes a “sanctuary” jurisdiction. The term typically refers to states, counties or cities that put some limits on how much their law enforcement agencies will cooperate with federal efforts to deport undocumented immigrants.

For example, sanctuary jurisdictions usually turn undocumented people over to Immigration and Customs Enforcement, the federal agency charged with policing illegal immigration, only if a federal arrest warrant has been issued, or if the person has been convicted of a serious crime. They generally will not turn in migrants for minor offenses like traffic violations.

The United States now has as many as 14 million undocumented immigrants. Sanctuary policies have generally been adopted in places with large immigrant populations, where widespread deportation efforts could cause the most disruption. Colorado, Illinois, Massachusetts and New York all have sanctuary policies, as do California, Connecticut, New Jersey, Oregon and Washington.

Many other states, including Alabama, Georgia, Florida, Iowa, Tennessee, Texas and West Virginia, have anti-sanctuary laws that compel local law enforcement agencies to cooperate with federal immigration authorities.

The mayors of New York City, Chicago, Denver and Boston have been called to testify before the House Oversight Committee about their policies. Those cities are among the communities that have dealt with a significant influx of migrants in recent years, including many bused to those places by Gov. Greg Abbott of Texas.

The resulting pressure on local resources has fueled criticism of the cities’ sanctuary policies — not only from longstanding opponents, but also from some local leaders in those places who once supported the idea.

President Trump and his allies have promised to take a hard line on immigration, and senior officials have made it clear that some of the cities that have embraced sanctuary policies would be targeted for enforcement actions.

In his cowboy boots and his Wrangler corduroy jacket, Mike Johnston of Denver knows how to dress the part of a Western mayor. And shortly after last November’s election, he turned President Trump’s promise of mass deportations into an O.K. Corral moment.

The first-term Democratic mayor told interviewers that he was willing to go to jail to stop unlawful immigration enforcement, and he envisioned resistance protests akin to the Tiananmen Square uprising in China.

Mr. Johnston, a former school principal and state legislator, has walked back some of his more defiant comments, but he is likely to be grilled about them at the hearing.

His message this time might sound more tame: Stand up for Denver’s embrace of immigrants, but also insist that the city is complying with federal immigration laws.

One of his chief antagonists at the hearing is likely to be Representative Lauren Boebert, a conservative Republican who represents a largely rural swath of eastern Colorado. Mr. Johnston and Ms. Boebert have sniped at each other on social media, and she is a vociferous critic of Denver’s more liberal politics.

The arrival of 42,000 migrants in the Colorado capital over the past two years tested the city’s welcoming posture. Many were bused from the southern border by Gov. Greg Abbott of Texas.

Then, during the presidential campaign, Mr. Trump spread false stories that Venezuelan gangs had taken over decrepit apartment buildings in a diverse working-class suburb of Denver.

Mr. Johnston likes to point out that despite the influx of migrants, crimes including homicides and auto thefts have fallen by double digits over the past year.

At the hearing, he may also reject the Republican characterization of Denver as a “sanctuary city.” Denver has never passed such an ordinance and works with Immigration and Customs Enforcement officers if they request information about a person already in detention.

But Mr. Johnston has said that Denver does not ask for people’s immigration status and that police officers do not participate in immigration raids. And state law limits cooperation between Colorado law enforcement agencies and immigration officers.

The four mayors testifying at a House hearing on Wednesday are confronting similar issues as they navigate their policies toward immigrants. But for Mayor Eric Adams of New York City, his challenge stands apart.

Mr. Adams, a Democrat who was indicted on federal corruption charges, has pledged to work with the Trump administration in its immigration enforcement efforts. The prosecutor overseeing his case, who resigned rather than drop the charges under pressure from the Trump administration, made a startling accusation: In exchange for leniency in his case, the mayor agreed to do President Trump’s bidding on immigration.

Mr. Adams has denied the allegations, arguing that he genuinely agrees with Mr. Trump on parts of his immigration agenda, such as deporting immigrants who are accused of violent crimes.

The mayor faces a balancing act at the hearing. He must appear relatively independent to Democrats back home who say he is beholden to Mr. Trump and also not anger Trump officials whom he has agreed to work with.

Mr. Adams recently appeared with Thomas Homan, the president’s “border czar,” in an interview on Fox News, to highlight their collaboration on immigration enforcement. Mr. Homan said he expected the mayor’s assistance or he would be “up his butt, saying, ‘Where the hell is the agreement we came to?’”

At the same time, Democrats who lead the New York City Council have made clear they will not work with Mr. Adams to weaken the city’s sanctuary laws, and many New Yorkers are worried about the prospect of mass deportations.

Mr. Adams is running for re-election in a crowded Democratic primary in June and has record-low approval ratings. Former Gov. Andrew M. Cuomo entered the race over the weekend and leads in polls, presenting a major challenge for the mayor.

Mr. Adams is still waiting for a judge to decide whether to drop the federal charges against him. After the Justice Department demanded that they be dropped, the federal prosecutor who resigned accused the mayor of a quid pro quo.

Two Democrats on the House Judiciary Committee began an investigation this week into the push to drop the charges against Mr. Adams and requested communications between the mayor’s lawyers and the Justice Department.

Mr. Adams understands the importance of the hearing. He has held a series of meetings with members of his legal team to prepare. The mayor said at a news conference on Monday that he would be “candid and honest” in his testimony and he appreciated the contributions of immigrants, but would not tolerate violent crime.

“It’s a privilege to be in this great country,” he said. “If you come here to violate our laws and abuse people, after you serve your time, you should not be in this country.”

It would be fair to say that Michelle Wu, the mayor of Boston, and the Trump administration do not get along.

Tom Homan, the Trump administration’s border czar, has threatened the city with increased immigration enforcement and suggested that the police chief should resign. “I’m coming to Boston, and I’m bringing hell with me,” he said last month.

Ms. Wu, a first-term Democrat, called the comments “clueless.”

A Harvard-educated progressive who speaks fluent Spanish, Ms. Wu, 40, has done little to retreat. She has instead spent time assuring immigrants that the city remains a safe and welcoming place.

A flashpoint in tensions between the Trump administration and the city is a local law known as the Trust Act. It prohibits Boston police officers from participating in most federal immigration enforcement actions, though they can assist in some cases when crimes have been committed.

Earlier this year, federal officials accused the Boston police of ignoring dozens of federal requests to detain undocumented immigrants. Police officials said that they had never received most of the requests because Immigration and Customs Enforcement had disregarded the department’s request in 2023 to submit its requests by email instead of fax.

Mayor Wu has defended the city’s approach as the best way to preserve trust between immigrant communities and law enforcement. And she promotes Boston’s public safety record: In 2024, there were 24 homicides, the lowest number since at least 1957.

Gov. Maura Healey has taken the brunt of the criticism, especially for the state’s failure to conduct criminal background checks on shelter residents. And Massachusetts had difficulty handling the 2023 surge in migrants.

Many of them arrived from Haiti, drawn to a long-established Haitian American community in Boston and the state’s longstanding right-to-shelter law. Contracts with motels and hotels cost Massachusetts hundreds of millions of dollars.

For her part, Mayor Wu, who is up for re-election this year, seems ready to spar during the hearing.

“I’m there, no matter how challenging the circumstances, to stand up for Boston, and also to stand up for the truth, the facts, of who we are,” Ms. Wu, a daughter of immigrants from Taiwan, told reporters when asked about the hearing.

“Some people are trying to paint a story of cities where immigrants live as dangerous places,” she said, “when in fact we are proof of the opposite.”