President Donald Trump claimed on Monday he had "somewhat compromising" information on an unidentified Democratic senator as he eviscerated the party for its handling of Brett Kavanaugh's Supreme Court nomination.

Trump exploded on Senate Judiciary Committee Democrats, alleging moral hypocrisy and unfair treatment of the appeals judge after a sexual assault accusation. Without naming the senator or providing any evidence, Trump suggested he had damaging information about a Democrat, whom he called "pretty aggressive."

"I've seen that person in very, very bad situations. Somewhat compromising. And you know, I think it's very unfair to bring up things like this," the president said during a news conference about the revised trade deal among the United States, Mexico and Canada.

Asked later who the senator is, Trump declined to name the lawmaker and said he would "save it for a book like everyone else." The president has a long history of making unfounded claims, then failing to provide evidence to back those assertions. The Supreme Court's term began Monday with only eight justices. Ford, who gave emotional testimony before the Judiciary Committee last week, has said she had no political motivation in coming forward and felt it was her "civic duty."

Kavanaugh angrily denied the accusations last week and had tense interactions with several Democrats on the Judiciary Committee. Facing requests from several key senators to delay a vote on Kavanaugh's confirmation, Trump asked the FBI on Friday to open a supplementary background investigation into Kavanaugh amid Ford's accusation and two other sexual misconduct claims.