I think you can feel fairly confident that the election will not be decided by your single vote. That being the case, I recommend that you consider voting for someone not tainted by promoting crimes against humanity. Besides imperialism, I refer to the Drug War and the prison-industrial complex.
Hidden in the word "vote" is the idea of vow or devotion, of making a gift which binds the giver to the receiver. There are things and people to which one should not bind oneself if one can avoid doing so; it is too depressing in both action and recollection.