I am having trouble fully understanding your response. (Please take this as a lack of understanding on my part, and not as an slight to how you communicate.) If it is okay with you, I would like to just summarize what you said to me, then you can tell me if I understood correctly or not, then I would rebuttal in a later post after I'm certain I understand your argument. I would much rather converse with the strongest version of the argument than argue with a straw-man my mind constructs.

P1 - You would happily vote for a (party that supports) alternative to democracy, unfortunately no such (proven) voting options exist.
P2 - The examples I cite are not valid because they explicitly advocated a new system, but that does not hold true for this election. Governments are not moved by internal forces (citizens voting) but by external forces, and actively work against both external change (which is known) and internal change (which most citizens do not see).
P3 - If voting could change anything, they wouldn't let us do it. :-) (As a side note, I thought Solidarity was a political/voting union? Though I should note that as a product of US schools, my knowledge on Soviet politics is lacking.)
P4 - Even violent revolution doesn't usually work. Revolutions do not overthrow governing systems; they merely change who is in power in those systems.
P5 - A possible solution to end democracy is a separate system arising that proves itself superior. Then the people vote for it or the government itself accepts the new system as superior. As proof, this is how the old Communist States died. (I actually did not know this. Probably due to the US's selective teaching of history.)
P6 - Humans rationalize our actions. By taking part in democracy, you become accepting of democracy; by not taking part in democracy, you become less so. To go out on a limb and put it in my own words, if you are hit on the head by a baseball bat every week you'll eventually rationalize why it's okay... but if you have to hit yourself every week, you'll rationalize that it's the most important/moral/good thing any person could ever do. (I'm a bit lost on the creepy/memetic argument though.)
P7 - By voting blue or green, you align blue or green. It poisons your perception of the world blue or green. And both blue and green support democracy, so voting for either one poisons your mind to support democracy.
P8 - The purpose of abstaining from voting is to prevent your mind (and your group's mind, eg lesswrong) from being poisoned, which is bad. (Furthermore, because of our size/influence, it does not cost us much to abstain.)

I believe that most of them are true on their face: P1, P3, P4, P6, P7. P6/7/8 strike me as especially good arguments against voting. I think P2 is incorrect, but I had extra trouble attempting to understand that paragraph, especially the second half of it; so that may only be due to my (lack of) understanding. I am undecided on P5 because I had not heard about that historical precedent until now and must research more (and if anyone has a short summary they could link to, I would love to read it). P8 is tricky... P8 is part of the wisdom of lesswrong that I disagreement with but haven't yet put into a post. I suspect that, unless I'm very wrong in my summary, my rebuttal will primarily concern itself with P8.

(As a side note, I feel I understand your post much better now and also disagree with it much less after doing a paragraph by paragraph summary/restatement. It is a surprisingly enjoyable experience to read something I disagree with make so many valid points.)

If it is not too much trouble, could you verify that I have summarized your points accurately and I'm not reading your post as a straw man? Also, any clarifications would certainly be appreciated. This is a subject on which I'm still not fully decided (though do I lean heavily to one side), so I am especially interested in knowing all the facts and arguments, even if they go against my belief in this case.

Edit: I haven't abandoned this post, but I'm going out of town this weekend to help my brother move into his new house. So, I'll be rather late with a reply.