Democratic presidential candidate Elizabeth Warren told WGBH News Saturday night that her biggest concern from the failed impeachment of President Donald Trump is that he will now conclude that “he can do anything.”

Speaking to WGBH’s Boston Public Radio, Warren said “it’s unimaginable” what Trump might do next.

“I can’t tell you how many times I’ve thought: Wow – that’s it – that’s as low as they can go without the Republican party jerking them up short, without the Republicans in the Senate saying ‘OK, that’s it, enough is enough,’” Warren said. “And then we wake up the next day and they’ve gone lower.”

After the Senate voted to acquit Trump of the impeachment charges, Maine Republican Sen. Susan Collins suggested that the impeachment process itself may have taught Trump a lesson. “I believe that he will be much more cautious in the future," she said.

But Warren said Saturday that is not what Trump learned. “You know what the lesson is that he learned? He can do anything,” she said.

Warren came in third in the Iowa caucuses last week and appears to be running in about the same spot in New Hampshire, according to recent polls. Democratic candidates are flooding the Granite State this weekend in advance of the first-in-the-nation primary Tuesday. Trump is also holding a rally in Manchester Monday evening.

Warren said she does not agree with the plan from former South Bend, Ind., Mayor Pete Buttigieg -- who appears to be gaining momentum after sharing first place in Iowa with Vermont Sen. Bernie Sanders -- to expand the number of seats on the Supreme Court to dilute conservative control of the high court.

“I just worry that we are going to make it more and more political,” Warren said. “And I just don’t want to go there. And I get it – the Republicans stole a seat,” by refusing to hold confirmation hearings for Merrick Garland, nominated by President Barack Obama in 2016.

Warren acknowledged that the Republican-controlled Senate is filling courts with conservative appointees. “We’ve for a long time now relied on the courts to watch out for the rights of the individual against the majority. A lot of that is shrinking up now. It means we are going to have to rely more on the legislative process and on the administration,” Warren said. But “making our whole judicial system even more political? That seems like a tough way to go.”