Mayor Wu, Mass. lawmakers speak ahead of Wednesday's ‘sanctuary city' testimony in D.C.

Boston Mayor Michelle Wu and members of the Massachusetts Congressional delegation held a press conference in Washington, D.C., on Tuesday, one day before the mayor is scheduled to testify before Congress.

Tuesday's press conference, is aimed at addressing the "damaging" impacts the Trump administration's actions are having on Massachusetts, organizers say. Sens. Elizabeth Warren and Ed Markey and Reps. Ayanna Pressley, Katherine Clark, Richard Neal, Jim McGovern, and Stephen Lynch were in attendance, along with guests they plan to bring to President Donald Trump's joint address to Congress.

Back home, a "People's State of the Union" protest is being held at 4 p.m. Tuesday on the Boston Common. The event was organized by 50501 Massachusetts, a movement committed to peaceful demonstrations to defend the Constitution and denounce overreach.

Republicans in Congress are taking aim at four cities — often called “sanctuary cities” — over their policies limiting cooperation with immigration enforcement with a hearing this week that comes as President Donald Trump presses ahead with his campaign of mass deportations.

The speakers focused on not just on the sanctuary cities issue, but also on things like the ongoing cuts to the federal workforce, concerns about Medicaid and federal funding cuts for health care research.

In addition to Wu, the mayors of Chicago, Denver and New York are set to appear Wednesday in front of the House Committee on Oversight and Government Reform.

There’s no strict definition for sanctuary policies or sanctuary cities, but the terms generally describe limited cooperation with Immigration and Customs Enforcement. ICE enforces U.S. immigration laws nationwide but seeks state and local help, particularly for large-scale deportations, requesting that police and sheriffs alert them to people it wants to deport and hold them until federal officers take custody.

But some cities and states say cooperating with ICE means victims of crime and witnesses who aren’t in the U.S. legally won’t come forward. And, to varying degrees, officials argue that they want their localities to be welcoming places for immigrants.

Courts have repeatedly upheld the legality of most sanctuary laws. But Trump administration officials have targeted sanctuary policies right out of the gate in his second term, seeing them as a key impediment to deporting people in the large numbers he wants. The administration has sued Chicago and Illinois as well as New York state over various immigration laws.

In Boston, the city's Trust Act generally restricts how much the police can cooperate with ICE, although it does allow some cooperation with a division called Homeland Security Investigations when it comes to such issues as combating human trafficking or drug and weapons trafficking.

The city also must follow a 2017 ruling by the state’s highest court that forbids Massachusetts authorities from holding a person otherwise entitled to release from custody based solely on a federal request.

Those requests, called detainers, typically ask federal, state, local and tribal law enforcement agencies to give at least 48 hours’ notice before suspected immigrants are released from jail — or to hold them for up to 48 hours after they would normally be released so ICE can pick them up. Otherwise, ICE must go out into the community to arrest them.

Trump’s border czar, Tom Homan, recently hammered Boston’s police commissioner and promised to go to Boston and “bring hell" with him.

That has not sat well in Boston.

Wu, a Democrat up for reelection this year, said that it was “clueless” and “insulting” for Homan to attack the police commissioner and that she wants Boston be a welcoming place for immigrants.

Asked Monday about testifying before Congress, Wu remarked that it's "Not my first rodeo," and said she'll be ready.

"We have already seen some materials put out in advance that seems designed to heighten interest and frame it as some kind of showdown or dramatic moment," she said. "I am going to represent the City of Boston, the amazing people who live here, work here who are making our community wonderful. I'm there no matter how challenging the circumstance is to stand up for Boston and also stand up for the truth, the facts of what we are."

The mayor's office confirmed Tuesday that the city will wind up paying an external law firm up to $650,000 for legal work related to the Congressional hearing, committee investigation and production of related documents. And that doesn't include the cost of prep sessions including staff from the mayor's office, law department, police and leaders from the mayor's cabinet.

The Associated Press contributed to this report.