You can vote against Trump if you want but that is throwing your vote away.
You Libertarians have helped the left quite a bit, such as Patty Murray.
Of course your party is radical left anyway.
Voting for a candidate you actually believe on never throwing your vote away.
Now voting for a party you know for a fact does not share your beliefs, will not try to do anything, and you will complain about insesantly... That is throwing you vote away.