IS IT A SIN TO VOTE FOR A DEMOCRAT?
Interesting question but probably not for the reason that most would expect.
The act of voting isn't sinful, per se, its the motive behind it that makes it good or evil. Whether you vote for a Democrat or a Republican, the fact is that you'll be voting for someone who will enact policies that further entrench into our society, the systematic murder of mostly black babies and so there is no way to vote for someone that you, as a Christian, should be affirmatively supporting. Affirmative support, however, is not the only motive behind the casting of a vote. American politics has devolved to the point where if a Christian votes at all it is going to be for the lesser of two evils. A better question then is....
Is it a sin to vote?
Again, it depends on the motive.
If you are affirmatively supporting either a Democrat or a Republican, the answer is probably, "Yes, it is!". If, on the other hand, you are casting a particular vote, not because you're necessarily a big fan of the person on that side of the ticket and believe in his leadership, but because the enemy of my enemy is my friend and one candidate is far worse of an enemy than the other, and your vote is intended to act as a societal preservative rather than being affirmative support, then that's a different thing. That is one way of being salt and light; to slow the progression toward tyranny and toward total social moral depravity, is it not?
There is a problem with this line of thinking though. The lesser of two evils is still evil and so, where does that thought process stop? How far down the rabbit hole of "the lesser of two evils" is too far? Do you vote for Mussolini over Hitler, do you vote for Putin over Stalin? At what point do two evils become so terrible that it no longer matters which is the lesser of the two? That's not a super easy question to answer, but if you desire for your vote to not be counted as a sin, I recommend you spend some time trying to answer it between now and November 5th.