WASHINGTON — Just hours after she pleaded not guilty to federal charges brought by the Trump administration, New Jersey Rep. LaMonica McIver was surrounded by dozens of supportive Democratic colleagues in the halls of the Capitol. The case, they argued, strikes at the heart of congressional power.

“If they can break LaMonica, they can break the House of Representatives,” said New York Rep. Yvette Clarke, chair of the Congressional Black Caucus.

Federal prosecutors allege that McIver interfered with law enforcement during a visit with two other House Democrats to an Immigration and Customs Enforcement facility in Newark, New Jersey. She calls the charges “baseless.”

It’s far from the only clash between congressional Democrats and the Republican administration as officials ramp up deportations of immigrants around the country.

Sen. Alex Padilla of California was forcibly removed by federal agents while attempting to speak at a news conference for Homeland Security Secretary Kristi Noem.

At least six groups of House Democrats have recently been denied entry to ICE detention centers. In early June, federal agents entered the district office of Rep. Jerry Nadler, D-N.Y., and briefly detained a staffer.

Congressional Republicans have largely dismissed Democrats’ behavior as inflammatory and inappropriate.

Often in the dark about the Trump administration’s moves, congressional Democrats are wrestling with how to perform their oversight duties at a time of roiling tensions with the White House and new restrictions on lawmakers visiting federal facilities.

“We have the authority to conduct oversight business, and clearly, House Republicans are not doing that oversight here,” said New Jersey Rep. Rob Menendez, one of the House Democrats who went with McIver to the Newark ICE facility.

The prospect of facing charges for once routine oversight activity has alarmed many congressional Democrats.

Lawmakers in both parties were also unnerved by the recent targeted shootings of two Minnesota lawmakers and the nation’s tense political atmosphere.

“It’s a moment that calls for personal courage of members of Congress,” said Rep. Summer Lee of Pennsylvania. “I wish that we had more physical protection. I think that’s one of those harsh realities that members of Congress who are not in leadership recognize: that oftentimes, we do this job at our own peril, and we do it anyway.”

The arrests and detentions of lawmakers have led some Democrats to take precautionary measures. Several have consulted with the House general counsel about their right to conduct oversight. Multiple lawmakers also sought personal legal counsel, while others have called for a review of congressional rules to provide greater protections.

As the minority party in the House, Democrats lack the subpoena power to force the White House to provide information. That’s a problem, they say, because the Trump administration is unusually secretive.

“There’s not a lot of transparency. From day to day, oftentimes, we’re learning about what’s happening at the same time as the rest of the nation,” said Rep. Lucy McBath, D-Ga., who led a prayer for McIver at the Capitol rally.

Democrats, to amplify their concerns, have turned to public letters, confronted officials at congressional hearings and digital and media outreach to try to create public pressure.

“We’ve been very successful when they come in before committees,” said Rep. Lauren Underwood of Illinois, who added that she believed the public inquiries have “one hundred percent” resonated with voters.

Still, many House Democrats concede that they can conduct little of their desired oversight until they are back in the majority.

Rep. Marc Veasey, D- Texas, said that “real oversight power and muscle” only comes “when you have a gavel.”