After Justice Antonin Scalia died on February 13, 2016, Senate majority leader Mitch McConnell said:

“The American people should have a voice in the selection of their next Supreme Court Justice. Therefore, this vacancy should not be filled until we have a new President.” (link)

At the time that Sen. McConnell made this statement, Pres. Obama had about 340 more days in office. What, you might ask, does this have to do with fuzzy logic?

In strict logic, a proposition is either true or false. In fuzzy logic, you have *probabilities* of a
proposition being true. For example, let’s say you have a frozen dinner whose instructions say ”Microwave
on high for 5 minutes.” If you microwave it for 4 minutes and 59.9 seconds, according to strict logic, the
meal is not cooked. (You did not give the meal exactly five minutes.) In fuzzy logic, you would assign a probability
of, say, 99.95% that the meal is sufficiently cooked to be safely eaten.
As the amount of time in the microwave decreases,
so does the probability that you can say that the meal is really cooked.
You’d assign a lesser probability to a meal that had
spent only 4 minutes and 30 seconds in the microwave, even less for 3 minutes,
down to a probability of 0.0001 (let’s say), for only one second of cooking time.

So, what does this have to do with the Supreme Court? There are probabilities that we can assign to how realistic it is for a President to make an appointment to the Court. If the vacancy occurs one second after the President is inaugurated, I’m pretty sure even Senator McConnell would agree that the President should not wait until the next election; an appointment at that time would be 100% legitimate. Similarly, even though the President holds office until their successor is inaugurated, it’s pretty clear that an appointment made one hour before the successor’s inauguration is nearly 0% reasonable.

Factoring out the amount of time it would take to get a confirmation,
the fuzzy logic question becomes “When is the President’s *effective* term of office over for appointments?”
The interesting edge case is election day, when the probabilities seem to shift dramatically. (Unlike the
microwave, where the probability is a fairly smooth function of time.)
But election day is not an issue in this case; it’s some nine months away, and the longest confirmation
process has been some 100 days, so there’s plenty of time for an appointment before then. Constitutional issues
aside, from a strictly mathematical standpoint I’d assign a very high probability to an appointment within
the next month being entirely reasonable. (No, it wouldn’t matter which party is in office. How much
I would *like* the result is another issue entirely, but it doesn’t affect the probabilities.)