One of them may agree with me on a single, small issue, the other doesn't.
The other?
There are more than two candidates.
Even if a 3rd (or 4th or fifth) party candidate doesn't have a chance of wining, a better showing in the election makes it, at least somewhat, easier for such parties to get press coverage and admission to national debates in the future.
This goes directly against the advice I responded to though - that if you don't vote for the lesser of two evils you are directly responsible for the greater of the two getting in.
I disagree with that stance. It appears you do as well.
The other?
There are more than two candidates.
Even if a 3rd (or 4th or fifth) party candidate doesn't have a chance of wining, a better showing in the election makes it, at least somewhat, easier for such parties to get press coverage and admission to national debates in the future.