I think I agree with orrion. If you want to vote, then vote. It shouldn't matter how many other votes there are or which side is winning, because nobody actually wins until the end of the voting period. If you don't care enough to vote regardless of the current vote count, then you just shouldn't vote at all because your heart is clearly not really in it.
The other thing, about people being convinced and changing their minds, should happen as a course of natural discussion regardless of whether or not the convincing post also included a vote.