The Senate Judiciary Committee is taking the right step in exploring the accusations that Supreme Court nominee Judge Brett M. Kavanaugh sexually assaulted a 15-year-old girl when he was 17 and is now lying about it.

Both the act itself and lying about what happened would disqualify Kavanaugh for appointment to the nation’s highest court.

The Judiciary Committee will, in essence, serve as a jury, questioning the accuser and the accused, assessing the veracity, consistency and plausibility of their stories and measuring their statements against what other facts are known, and they appear few.

The committee faces a stark choice. If Kavanaugh sticks with his story when he and Christine Blasey Ford testify on Monday, one of them will be committing perjury.

Blasey (she uses the surname professionally), now a psychology professor at Palo Alto University, contends she was at a Maryland house party when Kavanaugh forced her into a bedroom, locked the door, cranked up the music, pushed her onto the bed and began tearing at her clothes as he grinded his body against hers. Blasey says she recalls fearing she might suffocate from Kavanaugh’s hand, placed over her mouth to silence her.

Kavanaugh does not offer a different explanation of their encounter. He does not contend a lack of recollection. Instead, he flatly says there was no encounter. That none of it happened.

“This is a completely false allegation. I have never done anything like what the accuser describes — to her or to anyone. Because this never happened, I had no idea who was making the accusation until she identified herself yesterday,” read the statement issued by Kavanaugh.

The nominee has a motive to make an unequivocal denial. His reputation and appointment to the Supreme Court are at stake. Any acknowledgement that something happened, but nothing approaching the nature of Blasey’s accounts, would provide a crack that Democrats on the committee would be sure to pry at to attack his character.

Or he could simply be an innocent man facing a lie.

It is harder to come up with a reason why Blasey would create such a false narrative. She must know things will never be the same and that political operatives will place every aspect of her life under examination in an effort to discredit her. And facts will not get in the way of the smears she is sure to experience on social media.

Could she be undertaking all that as part of a political calculation to derail a Supreme Court nomination?

Far more likely is Blasey considers it the right thing to do, that in the spirit of the #metoo movement she cannot let a man who refuses to acknowledge and confront his actions as a teen to rise to such a powerful position over all our lives.

In its recent editorial, the Wall Street Journal suggests that Blasey is perhaps simply confused, creating false accusations resulting from the “vagaries of memory.”

“Mistaken identity is also possible,” wrote the Journal.

That’s an insulting approach taken to discredit many a sexual assault victim. Blasey is quite clear about what she remembers about an encounter that contributed to years of anxiety.

Yet there is no collaboration tied to the time. Blasey has said she told no one. The embarrassment and confusion Blasey felt, particularly given attitudes of the time period 36 years ago, make that completely understandable.

She did bring up the alleged assault, without naming those involved, in a 2012 couples therapy session with her husband.

For his part, Kavanaugh points to the corroborating account of his friend at the time, Mark Judge. Blasey has identified him as the other teen in the room at the time, saying she was able to escape when he also jumped on the bed. Judge says he recalls no such event.

But as the New York Times noted in its editorial, Judge also wrote the book “Wasted” about his excessive teenage drinking, his exploits, descent into alcoholism and eventual recovery. His partner in excess is a character named “Bart O’Kavanaugh.” The panel needs to hear from Mr. Judge as well.

Judge Kavanaugh appeared headed for confirmation, nothing disqualifying having arisen in the hearing process. That has changed. Senators on the committee should not use political prejudgment but fairly and objectively assess what they hear next week, then act accordingly.

The Day editorial board meets with political, business and community leaders to formulate editorial viewpoints. It is composed of President and Publisher Timothy Dwyer, Executive Editor Izaskun E. Larraneta, Owen Poole, copy editor, and Lisa McGinley, retired deputy managing editor. The board operates independently from The Day newsroom.