His comments on Tuesday, however, went further than before. Even as the president of Colombia sat next to him during what was supposed to be a diplomatic meeting between the two heads of state, Mr. Trump expressed aggravation and anger, taking on the latest accuser in more scathing and personal terms.

Without naming her, Mr. Trump singled out Deborah Ramirez, who said in an interview with The New Yorker published this week that Judge Kavanaugh exposed himself to her during a drinking party while they were students at Yale University.

“She said she was totally inebriated and she was all messed up and she doesn’t know it was him but it might have been him,” Mr. Trump said. Then, speaking sarcastically, he added, “Oh, gee, let’s not make him a Supreme Court judge because of that.”

Asked if Ms. Ramirez should be allowed to testify before the Senate Judiciary Committee, Mr. Trump questioned her reliability again: “The second accuser has nothing,” he said. “She thinks maybe it could have been him, maybe not. She admits that she was drunk. She admits time lapses. There were time lapses. This is a person, and this is a series of statements, that’s going to take one of the most talented and one of the greatest intellects from a judicial standpoint in our country, going to keep him off the United States Supreme Court?”

The president said he watched Judge Kavanaugh’s interview with Fox News on Monday in which he denied the allegations against him and suggested that he thought the nominee had been honest but not necessarily sure-footed. “He was so truthful,” Mr. Trump said. “You’re also not seeing him on his footing. This isn’t his footing,” he added. “He’s never been here before. He’s never had any charges like this, I mean charges come up from 36 years ago that are totally unsubstantiated.”

Democrats argued that Mr. Trump and other Republicans were casting a verdict without actually hearing from any accusers. “Senate Republicans promised that ‘anyone who comes forward as Dr. Ford has deserves to be heard,’” Senate Democrats said in a statement. “Unfortunately, it appears that Republican leaders have prejudged the outcome of Thursday’s hearing.”

Dr. Blasey has said that during a small high school party, a drunken Brett Kavanaugh pinned her to a bed, groped her, tried to remove her clothing and covered her mouth when she tried to scream. She said she escaped but never told anyone about it until decades later.