The FBI should reopen its background check into embattled U.S. Supreme Court nominee Judge Brett Kavanaugh without delay and do its best to confirm whatever facts it can surrounding the explosive sexual assault allegation from Prof. Christine Blasey Ford.

That should not be considered an extraordinary measure, as some critics paint it, or as something far afield from the FBI’s normal duties. The agency was charged with investigating Kavanaugh’s background before the confirmation hearings — standard procedure. In light of Ford’s allegation that Kavanaugh assaulted her while the two were in high school, it is entirely appropriate for the agency to perform additional checks.

The resistance by Republicans on the Senate Judiciary Committee verges on the absurd. The chairman, Sen. Charles Grassley of Iowa, has gone so far as to say that “nothing the FBI or any other investigator does would have any bearing on what Dr. Ford tells this committee,” ruling out any possibility that the agency would conduct any investigation before Ford testifying, as she has requested. Sen. Orrin Hatch, R-Utah, proclaimed that “the FBI does not do investigations like this.” President Donald Trump earlier this week said that “I don’t think the FBI should be involved because they don’t want to be involved.”

Curiously, Grassley and Hatch were on the Judiciary Committee that heard law Prof. Anita Hill allege sexual harassment on the job by then-nominee Clarence Thomas in 1991. They know that those allegations were sent to the White House, which promptly ordered an FBI investigation. Yes, there is some question as to how thorough the agency was in that case — it reported back within 72 hours that the claims were unfounded. But the FBI’s capability to undertake such an investigation — as well as the president’s authority to order it — cannot be questioned.

Equally curious is Grassley’s refusal to subpoena Mark Judge, named by Ford as the other young man in the room, who she said twice flung himself on Kavanaugh and her during the alleged assault. Judge, a conservative writer and recovering alcoholic, has written about his heavy drinking days at Georgetown Preparatory School, where he and Kavanaugh were classmates, including in a memoir that referenced the exploits of a “Bart O’Kavanaugh.” Judge has said he has no memories of the incident Ford described and does not wish to discuss the matter publicly. Unfortunately, when the stakes are this high, such wishes cannot always be honored. Judge should be subpoenaed, where he can make his denial under penalty of perjury.

Surely there are others who could speak to what happened at a party in 1982, particularly since Kavanaugh’s supporters were able to round up 65 women from high school days willing to attest to his character one day after the allegation surfaced. But finding them will take time — and the FBI.

Without an investigation of Ford’s claims, a hearing would become little more than a perfunctory speed bump, in which Senate Republicans would bring in a thoroughly prepped Kavanaugh while giving Ford and her allegations minimal consideration.

Ford, by the way, is now in virtual hiding, after being subjected to death threats, hacking of her private e-mail, doxing and other intimidation attempts, according to her lawyers. She has asked simply that her testimony come not in isolation, but as part of a law enforcement investigation.

If the assault never happened, as Kavanaugh has maintained, he should welcome the additional scrutiny. It would show that he is unafraid to face whatever findings are uncovered and, if there’s nothing to Ford’s allegation, allow him to take his seat on the court without suspicion hanging over his confirmation. That kind of courage and integrity should be requisite in a Supreme Court justice.