In the primaries, I tend to vote for the person I want to see in office. In the general election, I tend to vote against the person I don't want in office.

I'm saying "tend to" because sometimes I engage in strategic voting. I run through all the poll numbers I can find before the election. If there's any chance that my preferred "person who has a realistic chance of getting into office" might lose my district/state, then I'll vote for my preferred person.

But if there's no realistic chance that they'll lose my state - like, say I was a Democrat in California, then my vote for the president essentially doesn't matter. I mean, if Biden(Clinton/Obama/whoever) lost California, then there's realistically no way they'd have enough Electoral College votes to become president. So I can vote for whoever I want to for president - and I do.

Sometimes I do it for the money. The FEC has a thing where if a party/candidate gets 5% of the vote, they become eligible for federal matching funds the next election. Realistically, only the Democrats and Republicans benefit at the moment, but I'd like to see the pool expand so sometimes I vote in hopes that a group or person will qualify for matching funds.

And sometimes I do it to send a message. The parties spend a lot of money collecting and parsing data. So say I'm that Californian Democrat voting in 2020, where my vote will make absolutely no difference in who gets elected president, because California (as a voting bloc) is very Democratic. Since in that particular case, it doesn't make a difference in who I vote for for president, I can use my vote to send a pointed message to the Democrats: Hey, look, even in the general election, I voted for (and sometimes wrote in) this other candidate who is very into worker's rights and the environment. These are issues that are important to me, and you should keep that in mind when you're deciding policy.

Again, I don't do that sort of thing when there's even a chance my vote will make a difference. But if my vote isn't going to make a difference, then I'll try to make it count in some other way. I just wish all the people who refuse to vote because "my vote will never make a difference" would also go and vote. Maybe we'd actually get a semi-viable third party, or more influence over party platforms.