It seems that with National elections, there's a certain amount of Sophistry going on that has an intention of reducing the amount of choice that exercisers of their franchise might otherwise have.
There is the old "guilt them into voting ploy": "Bad politicians are elected by good people who do not vote." No, what about people who are dumb or misinformed or uninformed, but who vote anyway?
Another is the old saw that, "if you don't vote for a Democrat or Republican candidate, you are wasting your vote." There is presently the Green and Libertarian alternatives. And the Republicans are drawing close to a schism. There's nothing in prophesy that supports the idea that the Democratic and Republican parties are perpetual. After all, when was the last time you saw Whig candidates on your ballot?
Voting for a third or fourth party does register a lack of approval of either major party's candidates, or the two parties, themselves. Sometimes a "screw them vote" is implied by other choices.
And, once, I was so bummed out by both major parties' candidates that I didn't vote. But I did so righteously. I voted for neither clown.