WASHINGTON — Just hours ahead of a crucial vote on his confirmation, Supreme Court nominee Brett Kavanaugh said Thursday night that he might have been "too emotional" in his congressional testimony last week.

"I was very emotional last Thursday, more so than I have ever been. I might have been too emotional at times," he wrote in an op-ed headline "I am an Independent, Impartial Judge," published by The Wall Street Journal.

Kavanaugh testified last week before the Senate Judiciary Committee following testimony from Christine Blasey Ford, who has accused him of sexually assaulting her when they were in high school in the early 1980s.

"I know that my tone was sharp, and I said a few things I should not have said," he wrote in his op-ed. "I hope everyone can understand that I was there as a son, husband and dad. I testified with five people foremost in my mind: my mom, my dad, my wife, and most of all my daughters."

Kavanaugh said that his reaction — heavily criticized by Democrats as lacking in judicial temperament — was based in the fact that he had been subjected to "wrongful and sometimes vicious allegations," adding that his time in high school "has been ridiculously distorted."

"Against that backdrop, I testified before the Judiciary Committee last Thursday to defend my family, my good name and my lifetime of public service. My hearing testimony was forceful and passionate. That is because I forcefully and passionately denied the allegation against me," Kavanaugh said.

In his op-ed, Kavanaugh responded to critics who have said the tone of his congressional testimony — in which he said the allegations against him had been deployed for partisan purposes, and that political enemies were taking "revenge" on him for his work investigating former President Bill Clinton — raised questions about his ability to be impartial and nonpartisan.

"If confirmed by the Senate to serve on the Supreme Court, I will keep an open mind in every case and always strive to preserve the Constitution of the United States and the American rule of law," he wrote.

His comments came hours ahead of a key procedural vote that requires a simple majority that the Senate is set to take at 10:30 a.m. Friday on his nomination, which will determine whether it advances to a final floor vote, most likely on Saturday.

The op-ed also came on the heels of the release of the FBI's report of its speedy investigation into sexual misconduct allegations against him. Republicans said Thursday the report had vindicated him and Democrats blasted as incomplete.

Meanwhile, all eyes remain on four undecided senators: Republican Sens. Lisa Murkowski of Alaska, Susan Collins of Maine, and Jeff Flake of Arizona and Democratic Sen. Joe Manchin, D-W.Va.

Also Thursday, retired Supreme Court Justice John Paul Stevens, a lifelong Republican who was nominated by President Gerald Ford, reportedly said at an event in Boca Raton, Florida, that Kavanaugh does not belong on the high court.

"I thought [Kavanaugh] had the qualifications for the Supreme Court should he be selected," Stevens said, according to the Palm Beach Post. "I've changed my views for reasons that have no relationship to his intellectual ability...I feel his performance in the hearings ultimately changed my mind."