Protest and partisan divide appear to be only escalating as the U.S. Senate inches closer to a vote on U.S. Supreme Court nominee Brett Kavanaugh.

“I really feel like Senators have walked away without having the adequate information they need to make a decision,” said Sen. Patty Murray, D-Wash. “That's not good for the process.”

Murray read the 46-page FBI report earlier Thursday, as lawmakers take turns reading the single copy held in a secure room.

RELATED: What’s in the report

Senators cannot talk about what's in it, but a White House spokesman confirmed federal agents talked to nine people as part of their expanded background check, including Mark Judge, identified by Dr. Christine Blasey Ford as a witness to the alleged assault. Neither Ford nor Kavanaugh were interviewed by the FBI.

Blasey Ford claims Kavanaugh sexually assaulted her at a party in 1982 when they were teens.

“I am really frustrated and was very frustrated, because it was very narrow in scope in the number of people that were interviewed. What was telling to me was who was not interviewed—not asked questions,” said Murray.

Senate Republicans, meanwhile, argue the report contains no information to corroborate Blasey Ford’s allegations of sexual assault.

“There’s no way anything we did would satisfy the Democrats,” said Senate Majority Leader Mitch McConnell. “They’re dug in; you’ve seen it from the beginning.”

McConnell and Republican members of the Judiciary Committee loudly defended the report during a news conference Thursday. They also stressed continued support for Kavanaugh, in the face of a new letter signed by more than 2,000 law professors, including more than three dozen between Seattle University and University of Washington law schools. The professors write that Kavanaugh "displayed a lack of judicial temperament" during his testimony last week.

“I wasn't judging him as a judge. I was judging him as a human being who's having his life destroyed before his very eyes, having his 13-year-old daughter heartbroken, and his wife issued death threats,” said Sen. Thom Tillis, R-North Carolina. “I would defy anyone in this room, if they had gone through that same experience, if you wouldn't had those same emotions.”

In a new opinion piece for the Wall Street Journal, Kavanaugh wrote that he regretted his tone, at times, during last Thursday’s hearing.

“I hope everyone can understand that I was there as a son, husband and dad,” Kavanaugh writes.

“Going forward, you can count on me to be the same kind of judge and person I have been for my entire 28-year legal career: hardworking, even-keeled, open-minded, independent and dedicated to the Constitution and the public good,” he continued.

However, critics and Democratic Senators question not only his demeanor but his truthfulness during testimony.

“I really am concerned that we have a Supreme Court nominee who will be sitting on the court whose veracity will be in question,” said Murray.

Murray acknowledged she opposed Kavanaugh's nomination from day one, but she now worries about the impact of the process that’s unfolded and fears his confirmation could have a damaging impact on the judicial system and survivors of sexual assault.

“It will, I fear, send the wrong message,” said Murray. “The only way we can stop that is for women to stand up and speak out.”

Sen. Maria Cantwell, D-Wash., who's also up for re-election, declined an interview on Thursday but released a statement calling the FBI investigation incomplete.

“This FBI investigation brings up more questions than it answers,” Cantwell said. “The investigation is incomplete, and interviews were not completed with all witnesses despite direct requests from witnesses who wanted to talk to the FBI.”

RELATED: Procedural vote to advance Kavanaugh nomination scheduled for 10:30 a.m. Friday

Her Republican challenger Susan Hutchison says she would like the FBI report to be released to the American people, according to a spokesman.

Hutchison has not indicated whether she still supports Kavanaugh’s confirmation.

Kavanaugh needs only a simple majority of 51 votes to be confirmed, but Senate Republicans can only afford to lose one vote, in which case Vice President Mike Pence would serve as the tie-breaking vote.

Republican Sens. Susan Collins of Maine, Lisa Murkowski of Alaska, Jeff Flake of Arizona, and Democrat Joe Manchin of West Virginia have not revealed how they will vote, as of Thursday night.

RELATED: Where the crucial Swing senators stand via Vox