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

In another preview clip from his interview with Fox News that will air this evening, Trump said Vice President JD Vance is not his successor.

When asked if he views Vance as his successor, potentially becoming the Republican nominee in 2028, Trump responded, "No, but he's very capable."

"I mean, I don't think that it, you know, I think you have a lot of very capable people," he continued. "So far, I think he's doing a fantastic job. It's too early. We're just starting."

-ABC News' Hannah Demissie

A court officer confirmed that U.S. District Judge George A. O'Toole, Jr. does not intend to return to the bench Monday afternoon to make a decision on the federal buyout deadline.

Earlier Monday, a federal judge in Boston said he would continue to pause the Trump administration from carrying out its deferred resignation offer for thousands of federal employees until he issues a ruling on a preliminary injunction.

For now, the temporary restraining order from last week blocking the enforcement of the buyout offer remains in effect. If Judge O'Toole, Jr. does not issue a decision by midnight, OPM would not be permitted to enforce the deferred resignation plan.

-- ABC News' Peter Charalambous

Jacqueline Devine, a behavioral scientist who worked with USAID on HIV and AIDS prevention and treatment as a contractor, lost her job on Jan. 28. She received no advance notice and no severance.

"We all want to be more efficient and more effective. Yeah, nobody's contesting that, but an outright stop before you do any kind of critical review, just seems ... honestly, I got to use the word cruel," Devine said in an interview with ABC News.

Devine worries about the "trickle down" impact for global health as USAID is dismantled. But she also worries for her own career prospects, saying there are some moments where she's "freaked out, and I wake up and I can't fall back asleep because I'm thinking about, you know, what do I do at 65? My sector, my entire field, is gone. Where do I find work?"

Devine also said she's tried to avoid seeing Elon Musk's rhetoric about USAID.

"It would be laughable if it weren't -- the human impact to hear some of this," she said. "But it's hurtful to be called … 'crooks, we're crooks,' and, I'm sorry. I've, you know, put in an honest day's work, and everybody I know puts in more than an honest day's work, too."

-ABC News' Cheyenne Haslett and Meghan Mistry