I think that voting for third party candidates is a great way to move a cause forward if you live in a state (or district) that is locked into one of the partie

I think that voting for third party candidates is a great way to move a cause forward if you live in a state (or district) that is locked into one of the parties. If you care about the environment, vote for the green party. You won't change the outcome of the election but what you will change is the issues that the parties run on in the next election. For instance, if the Republicans lose your state by 5% but they see that the Green party won 2% of the vote, they will try to get that 2%. They will do this by adopting the Green Party's platform (third parties are usually very narrow so one of the big two can co-opt their entire platform). Now, you have a major party that is pushing for your agenda and you did it by voting in an election where "you vote doesn't count."