The comic is highlighting the absurdity of taking something that is technically undefined, and thinking that you’ve got a counter-factual (with is, like, exactly what is happening for most people in this thread).
If no felons have ever previously run for president, you have no data on how felons perform. You have an N of 0 because the event hasn’t occurred. Its a null result. NA. Undefined. You have no information. Its untested.
Even further, it highlights the very exact point of the comic, which is that when you rely on currently has an N of zero as a counter factual, you are going beyond the scope of what your data is capable of speaking to.
To assess the impact of a candidate with a felony on their chances of winning a presidential election, we need to know how many felons have run and how many have won. However, if no felon has ever run for president, we have zero data points for both felons running and winning. This means our calculation for the probability of a felon winning would involve dividing by zero, which is mathematically undefined and impossible. Without any previous instances to examine, we simply cannot make a statistically grounded prediction about the impact of a felony on a candidate’s electoral prospects; we lack any empirical evidence to base such an assessment on.