White House says some employees were fired by mistake

Sen. Susan Collins, R-Maine, said Monday afternoon that she will support Health and Human Services nominee Robert F. Kennedy Jr. -- whose full Senate confirmation could come as soon as mid-week -- after her conversation with him earlier in the day over funding cuts to the National Institutes of Health.

“He said he would re-examine them and seemed to understand” her concerns about potential slashing of NIH funding, Collins told reporters at the Capitol.

The senator’s support for Trump’s pick was previously uncertain, though she has broken with her party to oppose the confirmation of Pete Hegseth, the president’s nominee for defense secretary.

-ABC News’ Isabella Murray

Elizabeth Warren, who originally proposed the CFPB as a law professor, rallied protestors outside its office against Elon Musk as the Trump administration zeroes in on the agency.

"The CFPB is the little agency that has fought for us, and we are here today to fight for the CFPB," Warren told the crowd, calling the agency the "cop on the beat."

Warren directly went after Trump and Musk in her remarks, poking at Trump by calling Musk a "co-president.”

Maryland Sen. Chris Van Hollen also went after Musk in his comments, in addition to slamming Trump for giving him the "keys" to the U.S. government.

"This is the most corrupt bargain in American history. Elon Musk spent over $280 million to elect Donald Trump, and Donald Trump has given Elon Musk the keys to the United States government. Are we going to let that stand?" Van Hollen asked the crowd that responded “No!”

-ABC News’ Molly Nagle

During an hourlong hearing on the fate of the Trump administration’s buyout offer, a lawyer for the Department of Justice attempted to frame the deferred resignation offer as a “humane off-ramp” for federal employees before Trump enacts sweeping changes to “rebalance and reorganize the federal workforce.”

“President Trump campaigned on a promise to reform the federal workforce,” DOJ attorney Eric Hamilton said, outlining Trump’s return-to-office executive order and plan to reduce the size of the federal government. “We understand these announcements may have come as a disappointment for some in the federal workforce.”

Hamilton argued that any further delay of the buyout would cause irreparable harm because the Trump administration plans to enact the next steps of reshaping the federal government -- to “rebalance and reorganize the federal workforce” -- as soon as the buyout window closes.

Sen. Dick Durbin, the top Democrat on the Senate Judiciary Committee, told ABC News that he reads Vice President JD Vance's assertion that "judges are not allowed to defy the executive's legitimate power" as "one step away from a constitutional crisis.”

"Let's be very blunt about this. If he believes the executive branch can ignore directives coming down from the judicial branch it is an invitation to a constitutional crisis," Durbin said.

When asked what if anything could be done to push back, Durbin said they'd have to "hope the courts rule the proper way, the rationale way, so we have a position to defend.”

He added that the vice president’s comments are “one of the most irresponsible statements” he has ever heard “from a highly elected official in our country” and that it has a “chilling effect” on Congress.

-ABC News’ Allie Pecorin