The Washington PostDemocracy Dies in Darkness

Here’s why only Hillary Clinton and Donald Trump — at most — will make the debates

Republican presidential candidate Mitt Romney (L) and U.S. President Barack Obama talk over each other as they answer questions during a town hall style debate at Hofstra University October 16, 2012 in Hempstead, New York. (John Moore/Getty Images)

It's safe to say that being included in the three prime-time presidential debates is central to the long-shot candidacy of Libertarian Gary Johnson. Being given a chance to speak to an audience of millions of people alongside the candidates from the two major political parties is the sort of thing that could vault his poll numbers from the single-digits into something approaching contention.

But the catch-22, of course, is that with poll numbers that low, he doesn't get included.

On Monday, the Commission on Presidential Debates released the criteria it will use to grant access to candidates in the debates, scheduled for last September and October. (Any presidential candidate that makes the cut will see his or her vice presidential candidate included in the vice presidential debate.) They are two-fold: A candidate has to be at at least 15 percent by mid-September in five national polls conducted by The Post/ABC News, CBS/The New York Times, Fox News, CNN/ORC and NBC/Wall Street Journal and the candidate has to be on the ballot in enough states to be able to conceivably win 270 electoral votes.

We can apply those criteria right now to give a picture of who might be included.

In polling at this point, it's Donald Trump and Hillary Clinton, and that's it. Johnson's still under 10 percent on average, and the Green Party's Jill Stein is below 5 percent. Even McMullin, the even-longer-shot independent candidate that announced earlier this month, isn't even included in these polls. (Stein was only included in three of them.)

Both Johnson and Stein will be on the ballot in enough states to hit the 270 electoral vote mark (according to their parties' websites). McMullin is shut out again, though, with only 19 electoral votes possible as of writing.

This raises an interesting alternative scenario: What if Trump drops out? There's almost no chance that he will, of course. If he were to do so, the Republican Party's difficult scramble to replace him on the ballot in every state -- a process that would require going to court in many states -- could imperil their replacement candidate being able to accumulate 270 electoral votes by the time of the debate.

As it stands, the most likely scenario is the one we've always expected: Trump and Clinton face off in three debates and Tim Kaine and Mike Pence debate in one. That is, assuming that Trump actually debates.

If he doesn't, Gary Johnson would no doubt be happy to fill in.