5. I can't vote for Romney because of my conscience.
Ah! Conscience! We can't violate our conscience. It's what convicts us and approves of us (cf. Rom 2) so that we know right from wrong.
You know: except for the people in Romans 1, right? Those people have a lousy conscience because of their idolatry, and they are given over to all manner of sin because of it.
I can't peer into your conscience, OK? I can't unpack it's sanctification or its lack thereof. What I can do, however, is offer it at least one observation that it has not considered deeply enough: of the two men running for the office of President this year who have a mathematical chance of winning, one of them has not spent his political career and public life trading on fear and hatred; the other one has. If you think it's OK to simply allow the career politician to win this election -- which is what not voting against him will accomplish -- then by all means, sit it out.
We'll see how your conscience feels in 4 years.