Trump's tweets follow an interview he gave to Fox's Sean Hannity on Thursday night in Las Vegas, where he appeared at a rally, in which the president first questioned why the FBI hadn't been called at the time of the alleged assault (which would likely have been handled by local law enforcement).
"You say, why didn't somebody call the FBI 36 years ago?" Trump asked. "I mean, you could also say when did this all happen, what is going on?
"To take a man like this and besmirch — now, with that being said, let her have her say and let's see how it all works out. But I don't think you can delay it any longer."
In an appearance in Portland on Friday, Sen. Susan Collins, R-Maine, said she was appalled by Trump's tweet.
"First of all, we know that allegations of sexual assault – I'm not saying that's what happened in this case – but we know allegations of sexual assault are one of the most unreported crimes that exist. So I thought that the president's tweet was completely inappropriate and wrong," Collins said.
Trump's tweets came amid ongoing negotiations over whether and how Ford and Kavanaugh might testify before the Judiciary Committee. The committee initially scheduled a hearing for Monday and had invited Kavanaugh and Ford to testify. In a letter to the committee, Ford's lawyers said that she would be open to appearing before the panel, but that an appearance Monday "was not possible." Ford's lawyers and Democrats on the panel want the FBI to investigate the charges, a move Grassley and other Republicans have dismissed.
Ford does not want Kavanaugh in the room when she testifies, and her team does not want an outside questioner on the Republican side to be brought in, a source in Ford's camp tells NPR's Nina Totenberg.
On Friday, Grassley's camp agreed to the demand that Kavanaugh not be in the committee room, but rejected her request to only allow senators to question the two witnesses, saying it was within committee rules to permit staff attorneys to conduct the questioning.
Grassley's Friday night letter to Ford's attorneys setting a deadline also rejected two key requests discussed in a conference call with committee staff from both parties on Thursday: to have Kavanaugh testify first and for the committee to subpoena other witnesses like Mark Judge. Ford alleges Judge was there at the time the incident took place when they were in high school.
Ford says that Kavanaugh groped her and tried to forcibly remove her clothes during a house party in Bethesda, Md., in the early 1980s. Kavanaugh has denied the accusation.
In another tweet Friday morning, Trump called Kavanaugh "a fine man," who he said is under assault "by radical left wing politicians who don't want to know the answers, they just want to destroy and delay." Trump continued, "I go through this with them ever single day in D.C."