This question originally appeared on Quora. 
Answer by Joshua Engel, Polymath
America is a nation of 300,000,000 people. We select one President.
You were not being asked for your favorite person. You were not being asked for every detail of your views. You were not being asked for your preferred policy.
You were being asked one question: after multiple rounds, we've narrowed it down to two choices. Which one do you prefer?
That's it. That's all there is.
If you went there yesterday and told yourself that it doesn't matter which one you vote for, or if you vote at all, or that voting for some unknown candidate is a more honestly progressive answer to the question, then you are failing to be intellectually honest: you know that those put the less progressive candidate in office. You voted to take the nation a lot backwards instead of a little forwards.
Once the vote is cast, you can yell and scream and run for office and make phone calls and hoist signs and do everything you possibly can to influence him to be more progressive. You can despise every anti-progressive compromise he makes. That's dissent, and dissent is patriotic.
But when it comes to your vote, failing to vote for "the lesser of two evils" gives you "the greater of two evils." If your conscience is good with that, then there's really nothing I've got for you, except to be bitter that you could have made life better and instead made it worse.
I'm not asking you to ignore Obama's flaws. I'm asking you to reject the self-serving arguments of those hatemongers who want to ruin your life by taking advantage of your hand-wringing that you didn't get everything you want in your President.
You want me to tell you Obama's the greatest progressive ever? Don't bother. I do happen to have this open at the moment:
"Most progressive" is different from "progressive." Like I said, today, Wednesday, we go back to fighting over policy. But yesterday, it was about politics, and whether we were going to let the masters of the politics of personal destruction on Fox News win. Because we can't be progressive if there isn't a country to be progressive in. And I assure you, if they had destroyed the closest thing we've had to a progressive in a half-century by lies, racism, obstructionism, and hate, then we really wouldn't have had a country left.