The scheduled testimony by Judge Brett Kavanaugh, responding to Christine Blasey Ford's accusation of sexual assault in the early 1980s, raises a central question: With respect to that accusation, who has the burden of proof?
The answer might turn out to be decisive to Kavanaugh's prospects for confirmation.
Invoking the standard used in criminal law, some people have said that Kavanaugh should be presumed innocent. Others say that senators should avoid any presumption and ask instead: Who is more credible? Who is the most likely to be telling the truth?
It's not so simple.
To ensure political neutrality and to cool emotions, let's try to put the current controversy to one side. Let's insist on bracketing any judgments about Kavanaugh in particular, and about what might or might not have happened several decades ago.
Instead, let's ask a more general question: How should officials deal with an accusation that a potential Supreme Court justice has committed a violent crime? To make things simple, let's stipulate (without necessarily agreeing) that if the individual did commit that crime, he or she would be disqualified.
Suppose that a president, considering a large number of possible nominees, concludes that there is a 30 percent chance that an accusation against an otherwise superb contender is true. No president would be likely to nominate such a candidate. Apart from the inevitable political fight, no president is likely to think that of dozens or hundreds of highly qualified people, the very best choice for such an important position is someone who might well have committed a violent crime.
We could make the case harder by lowering the probabilities. Suppose that a president thinks that guilt is 20 percent likely, or 10 percent likely, or 5 percent likely. If the number approaches zero, a president might proceed to nominate the individual in question, thinking: I am not going to make my decision on the basis of unfounded accusations. But if the president believes that the likelihood of guilt is significant, another candidate will be chosen.
That brings us to the key question: Is the U.S. Senate any different?
Suppose that senators believe that the allegations are probably false, but 30 percent likely to be true. There is a strong argument that confirmation would be a terrible idea. Why should the Senate consent to a Supreme Court appointment for someone who might well have committed a disqualifying act?
There are two countervailing considerations. First, a refusal to confirm a nominee is a pretty hostile act – especially if it is based on an accusation of criminal behavior. It is far more personal, and much more of a negative stain, than a president's decision not to nominate someone in the first instance. Reasonable senators might well be reluctant to vote against a nominee on the basis of an accusation that they do not, on balance, believe to be true.
Second, the Senate owes the president a degree of deference. We can argue about how much. But the president's job is to select the very best person for the job, which means that he has discretion to decide against potential nominees for any number of reasons. The Senate's job is much narrower. It is to decide whether the president's choice is unfit for the job.
These considerations suggest that senators might think that if a nominee to the Supreme Court has been accused of a disqualifying crime, the question is: Is it more likely than not that he did it? That's not crazy, but on reflection, it's probably wrong.
The Senate isn't a court of law. Senators are entitled to vote against confirmation of a Supreme Court nominee if they conclude that there is an undue risk that a nominee would be careless with the law, unfair to litigants or some kind of extremist.
If senators conclude that there is a significant chance that a nominee committed a crime of violence, they are entitled to oppose confirmation – even if they think it more likely than not that the nominee is innocent.