For a third-party candidate to have an actual chance, he or she would have to be somebody who could plausibly serve as president if elected. As a popular two-term Republican governor in a deep-blue state, Hogan himself would at least clear this threshold — unlike, say, Evan McMullin in 2016.

If Hogan or another plausible contender did decide to hop in, a major challenge would be to overcome the stigma of being dismissed as a mere vehicle for protest. It’s one thing to poll at 5 or 10 percent, but to poll in the 20s or 30s, and be seen as a genuine threat, is much different. …

All of this said, even if a third-party candidate could reach the point of having plurality support nationally, it becomes much more difficult to envision a scenario in which such a candidate wins 270 votes in the Electoral College.

[It’s even harder to envisage such a candidate organizing effectively enough to get on the ballot in time for the election, especially if they wait until April or May to see if both parties nominate their incumbents. Ross Perot did it by spending a large amount of his own money and effectively organizing minor parties into the national Reform Party, but that was no easy task — and Perot didn’t win a single Electoral College elector, either. — Ed]