When a tape emerged in early October 2016 of Donald Trump declaring in vulgar terms what he could get away with doing to women, the Star Tribune Editorial Board called for him to leave the presidential race. No one who regarded half the populace with such contempt could lead the nation with decency, the board wrote.

This year, presumptive Democratic presidential nominee Joe Biden is accused of doing to a woman what Trump bragged about. Biden said in an interview last week with MSNBC's Mika Brzezinski that it "never, never happened." But if the allegation is shown to be true, the same principle will apply.

If true. So much depends on that, and it would benefit both Biden's party and the nation to know — or at least deduce the degree to which it can be known — sooner rather than later. Biden can help more than he has so far.

The accuser is Tara Reade, who once worked in Biden's U.S. Senate office. She alleges a 1993 incident in which Biden pushed her against a wall, slid his hand up her skirt and penetrated her with his fingers. It's an extraordinary claim that, as the saying goes, requires extraordinary evidence. Yet it has arrived within a larger context: the historical pattern of neglect toward sexual misconduct allegations that the MeToo movement of recent years has set out to remedy.

Questions have been raised about Reade's account. Among them: She supported Bernie Sanders this year for president — why did her allegation coincide with Biden's emergence as the leader in the Democratic race, and why hadn't she provided the detail when she and other women went public last year with complaints about his tendency to intrude upon personal space? And if she filed a workplace complaint at the time of the alleged incident as she says, what did it specify and why can't she produce a copy?

Inconclusive information about the distant past and questions about motive and reliability will be familiar to those remembering the dispute over Brett Kavanaugh's nomination to the U.S. Supreme Court a year and a half ago. Kavanaugh's supporters were dismayed by the credulity with which many of his opponents accepted Christine Blasey Ford's recollection of being sexually assaulted by him when both were teenagers. The relative forbearance Biden is getting strikes them as hypocrisy.

The Editorial Board did not take a definitive stance on the veracity of the allegations against Kavanaugh but faulted those with a stake in the investigative process for failing to allow the pursuit of all possible avenues of information. We take a similar position now.

Any employment complaint filed by Reade would be one such piece of context but appears inaccessible. To his credit, Biden asked the secretary of the U.S. Senate to do a search; the reply came that the release of such a record, if found, would be prohibited under the law.

Biden has resisted interest in another set of information that is within his power to make available — 1,875 boxes of "photographs, documents, videotapes, and files" and 415 gigabytes of electronic records covering his 36-year Senate career. It's archived at the University of Delaware, his alma mater, for release after his retirement from public service.

Biden isn't eager to offer anything that might be used against him in the campaign, whether related to Reade or to his myriad other interactions as a senator. He also says his papers wouldn't include personnel records. These obstacles can be overcome. An independent investigation — perhaps arranged by the Democratic National Committee, which has cause for handling the matter with care but also a stake in an unbiased answer that would prevent the need for the party to scramble later — could determine whether any documents relevant to Reade exist in the archive, and if so, publicly release only those.

Moreover, Biden can tell his side of the story in more detail. The invasive encounter Reade describes is not the only one she has cited as making her uncomfortable. By his account, then, how well did he know her when she worked for him? What interactions does he recall? He sidestepped an opportunity to address these specifics in his interview with Brzezinski.

More information would equal more opportunity for verification. Biden has received support from fellow politicians, including Minnesota Sen. Amy Klobuchar, a potential running mate, and South Carolina Sen. Lindsey Graham, a Republican, but members of the public can only surmise what additional context they may have.

Some may complain — in fact, already have — that the entire affair is becoming the 2020 version of the "but her e-mails" expedition that dogged Hillary Clinton's presidential candidacy in 2016. Some may place a higher emphasis on Biden's efforts on behalf of women (as did supporters of Kavanaugh in favor of their man). A final and hardly insubstantial concern is a double-standard involving Trump, who has been accused by more than two dozen women of sexual assault yet seems impervious to review.

Indeed, there are many what-ifs and what-abouts in this situation. But Biden himself has defined the principles that should apply when the details are complicated. In a statement last week on Medium, he wrote: "One is that women deserve to be treated with dignity and respect, and when they step forward they should be heard, not silenced. The second is that their stories should be subject to appropriate inquiry and scrutiny."

His thinking appears to have evolved since the Kavanaugh hearings, but it's on the mark now. We'd add that any decent inquiry would gather more information than it ultimately needs.