Here's an article by muse-ican Derek Webb on the Christian's right to vote or not, based on their conscience. While I normally don't write to any author, I felt that I had to respond. Just please read the article before you read my response.
interesting article. just two quick thoughts. first, the US is a republic if i remember correctly. second, what about another objection that states that if you don't vote, then you abdicate your right to complain, criticize, or disagree with anything political at local, state, or national levels? also, there are other things to vote on besides who you want to be president, things that will possibly impact your relationship with your neighbor (ie funding for education, property taxes, etc).
this reminds me of a poster i have on my wall in my classroom. it has a triangle with the words "rescuers" at one point, "bystanders" the other, and "perpetrators" at the last point. in the middle it has the word "victim". the poster, gotten from a holocaust museum, simply asks, "which role do you choose?". we fit somewhere in it, like our political process, like it or not.
i think i understand your basic point and agree with most of it. you can't violate your conscience, if it's based on the understanding of God's will as revealed in His Word. martin luther spoke up to the injustices and infidelities of the church when most did not. he got involved when he saw the "spokesperson" of God going against what God's Word says. but he also didn't go against his conscience based on "...scripture and plain reason alone." i guess i just don't like the whole pinocchio idea of always letting your conscience (alone) be your guide. your conscience must be based on or from something. something that is bigger than you. for the body of Christ, that should be evident.
anyway, just thought i would share these thoughts.