Brett Kavanaugh's Supreme Court nomination is in crisis. So is our commitment to impartial justice and due process.

A woman came forward to a Democratic lawmaker in early July to pass along an accusation that Kavanaugh sexually assaulted her at a party during their high school years in the 1980s. Christine Blasey Ford wanted to remain anonymous at the time, but has finally put her name on the allegation.

Ford, whom the Senate would like to question along with Kavanaugh next week, has so far not named the date, place, or any contemporaneous corroboration that any incident occurred. Her first point of corroboration was from decades later, when she told a therapist in a counseling session about the alleged assault. (The therapist's notes from several years ago reflect this.) For his part, Kavanaugh denies all the allegations against him.

Americans will have to judge for themselves whether Ford's testimony and allegations are credible. Because as is, her word is essentially all we have to back up her claims.

Sexual assault is a serious crime. It should be taken seriously when alleged. No one should doubt that a scenario like the one described by Ford takes place far too often, when drinking leads to assaults of varying degrees at parties where one believes they are surrounded by friends. It's also reasonable to assume that a terrified teenage girl would want to keep such an attack quiet, for a number of reasons.

However ... we have a principle in American jurisprudence that goes back to the writing of our Constitution. It establishes a presumption of innocence in a crime until proven guilty. Kavanaugh is not being prosecuted now, but the values remain the same.

Unfortunately, that shared sense of American justice seems to have vanished. In its place are demands to assume that allegations are true, with the burden of proof on the accused to disprove them.

Some have argued that America's tradition of justice — that we must presume innocence until guilt is proven — shouldn't apply to this case because the only consequence of forcing Kavanaugh to prove a negative is that he won't get the Supreme Court job. "But what if it's true?" people ask, arguing that the mere allegation has somehow changed the nature of the person nominated, even if the charge is unproven.

Former Vice President Joe Biden argued explicitly for this standard whenever allegations involve prominent men. "You've got to start off with the presumption that at least the essence of what she's talking about is real," Biden told reporters on Monday, "whether or not she forgets facts, whether or not it's been made worse or better over time." This, however, sets up a dangerous double standard for public service that presents a threat to rational governance as well as to our tradition of justice.

Shifting the burden of proof on Senate confirmations, appointments, and elections changes all the incentives for public service. If we are not to evaluate claims on "facts" in order to determine whether the "essence" actually is "real," then what should form the basis of our evaluation? Whether or not we like the accused? Which party does he or she represent, or which party appointed him?

This is not a recipe for justice, but instead an environment for bare-knuckled politics and a breeding ground for a return to Salem circa 1692. Such an environment will repel men and women of goodwill and good character from public service, incentivizing only the most insensitive and impervious personalities to choose to serve. That will lead to even further degradation of public discourse and an erosion of trust in institutions, which will make witch hunts and smear campaigns even more likely.

In this particular instance, we have a nominee who has a long track record of public service, both in law and politics, with nary a hint of dishonor until this allegation surfaced. Justice requires allowing the accuser to make her claim, but also in applying judgment in whether evidence exists to establish a crime and then whether it points to guilt.

Maybe Ford is right. Maybe Kavanaugh is guilty. But we must presume his innocence until guilt is actually proven.

Otherwise, what does justice in America even stand for?

Author's note: In writing that "we must presume his innocence until guilt is actually proven," I inadvertently set a criminal-conviction standard for vetting people for public service, which is not what I intended — but is a reasonable criticism of what I wrote. What I meant to argue was that justice requires allowing the accuser to make her claim, but also in applying judgment in whether evidence exists to establish a crime and then whether it points to guilt. If we brand Kavanaugh guilty and drum him from the public square without evidence, then we will have created incentives that value character assassination above actual character.