The Argument Levied Against "Third-Party" Voters
When you don't find either the Republican or Democratic candidate acceptable, so choose to vote third party, people make some pretty ridiculous claims.* One of these is that either the Republican or the Democrat is going to win anyway, so we have to stand up for what's right by picking the slightly-less-awful candidate, and voting third party is stupid, lazy, or some similar variation.
If that logic is sound, then it also is irrational to bar the door against a would-be thief, because the probability is he's just going to manage to steal your stuff anyway, so you should just help him by opening the door and letting him walk in.
Let's Continue that Train of Thought...
The "sensible" thing to do when someone wants to rape you is to just strip everything off and make it easy, because it's "inevitable."
You should hand your child over to the person who wants to kidnap him, because you're not very strong, so fighting back probably won't be effective.
Not What the Founders Had in Mind
It is sad that we've fallen so far as a nation that someone protesting what he believes is wrong, by voting for someone he can conscientiously support, is not only mocked and harassed for "wasting his vote," but also pushed to accept the false notion that to avoid supporting something that's 99% rotten is to inherently support something that's 100% rotten. That's un-American, folks.
(borrowed from my Facebook page)
*This is not meant as commentary on whether the reader should consider neither candidate acceptable, but as commentary on the logic used against those who honestly find both unacceptable.