Cogent rebuttal to anyone thinking about voting for a third-party candidate, or even worse, “not voting”:

But it doesn’t matter what message you think you are sending, because no one will receive it. No one is listening. The system is set up so that every choice other than ‘R’ or ‘D’ boils down to “I defer to the judgement of my fellow citizens.” It’s easy to argue that our system shouldn’t work like that. It’s impossible to argue it doesn’t work like that.

Of course, as in most things, The Simpsons Already Did It™.