i mean, if there was some third option that could actually win, it would be a different story. he would then be endorsing clinton over that third candidate, and that would be egregious. but, that third option doesn't exist. it's really hillary or trump. those are your shitty choices.
i'm not a senator, so i don't have a responsibility to be responsible and i can go ahead and endorse stein, fully aware that it might elect trump. that's the freedom you have when you have no intention of actually running for office, right?