Timothy Stanley is a historian and columnist for Britain's Daily Telegraph. He is the author of "Citizen Hollywood: How the Collaboration Between LA and DC Revolutionized American Politics." The opinions expressed in this commentary are his. View more opinion articles on CNN.

(CNN) The Brett Kavanaugh hearings feel like a decision moment in American life when everyone has to choose where they stand. The problem is wherever that position is, it is permeated with doubt.

Timothy Stanley

The Supreme Court nomination of Kavanaugh had been pretty much going as planned until news broke that he is accused by Christine Blasey Ford of sexual assault. They are both expected to testify on the matter soon before the Senate Judiciary Committee.

The alleged assault occurred at a party in the 1980s when Kavanaugh and Ford were teenagers. Proving such a thing is very hard; it becomes, absent corroborating evidence, a case of one account against another. If Ford is lying, it's the most monstrous lie imaginable. If she's telling the truth, what Kavanaugh did was horrendous, and he clearly has no place in the judiciary at all.

For conservatives, however, the truth -- which, to repeat, may remain frustratingly ambiguous -- is only one part of the political calculation. The challenge they face is this: If they drop Kavanaugh, then they fear it will send a message that a career can be stopped by an unproved allegation, and that's not a precedent they care to set. But if they stand by Kavanaugh and he makes it to the Supreme Court, they could be stuck with a man on the bench haunted by the accusation of sexual assault.

And given that Kavanaugh is socially conservative -- possibly even the much-dreamed-of deciding vote to overturn Roe v. Wade -- his appointment is both everything the right has ever wanted and, suddenly, something to be cautious about.

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