Clay makes some decent points but misses the boat on two:

1. Third parties can sometimes win, and have, when one of the major parties implodes and a third party soon moves in to become the new second party. Whigs went out, Lincoln’s Republicans came in. If you think Donald Trump is doing to today’s Republican Party what Zachary Taylor did to his Whigs, a vote for Gary Johnson is not a meaningless vote for the Republican Party to become more libertarian, nor even for it to DIAF. It’s tantamount to acknowledging the GOP is dying anyway, and voting early for Johnson’s moderate version of the Libertarian Party — rather than, say, the Ted Cruz Party — to be its replacement.
2. Completely missed the point about safe-state voting. If a third party vote in a solidly red/blue state is a farce, so too is voting for the major parties there. Why waste your time voting for the major party candidate, who doesn’t need your vote, or his challenger who can’t use it? Might as well stay home and play Tiddlywinks rathan wasting your time voting at all. If you support the dominant candidate, you already “voted” for him with your feet by admitting to the last U.S. Census that you lived in that state — thereby “voting” for it to have one more electoral vote his party can consistently rely on. Conversely, the only way to effectively “vote” against that same party is to leave, or at least convince the next Census that you did. If you think votes for Democrats and Republicans in safely red or blue states matter — and I do think they do — then surely third party votes do as well.