from the standpoint of law, if i vote for someone, pretending for a moment that my vote counts, and that person is elected, then, they use their power to cause injury to anyone, technically, i am lawfully responsible for that injury. people tried at Nuremburg were not allowed to claim, "i was only following orders" there is not a candidate that i've seen that i trust with my vote. voting for any ruler over others is philosophically immoral.
RE: A mathematical explanation how voting third party in 2016 is the only vote that counts