Face it: there are only two candidates who realistically have a chance at winning the general election. It’s been that way for every US election we’ve seen.

If you vote for someone who doesn’t have a realistic chance of winning, that’s about the same as just not voting at all.

So you really have 3 choices: candidate A, candidate B, or indifference.

And there are two possible outcomes: candidate A or candidate B.

If one of those outcomes is at all preferable to the other, (e.g. either A is “better” or B is “worse”), it’s strategically best to vote for the main candidate you prefer, since that increases the chance of getting your preference of the two outcomes.