I don't like to get political in this forum, but you need to get a grip. It isn't an either/or choice. Most ballots have several choices for president, including Green, Libertarian, and Constitutional parties (with apologies to other parties I've omitted). Your naive plea here plays a small part in propogating the two-party lie that is a major source of tyranny in the United States.
It doesn't decide the president - but it influences which positions the 2 major parties have to cover. Lets say for example democrats are losing because they lost massively votes to the green party - then in the next race they will certainly consider how to get those votes back and might have a greener agenda.
Quit it.