A vote for a third party may just be vote for who you want to win. To say you should vote for someone who will help Trump to lose adds up to a democratic deficit. My parliamentary constituency is North Cornwall. It's been held in the past by the Liberal Democrats, who I revile. In recent years it's been held by the Tories, who I revile even more. Far more, in fact. My sentiment is to always vote Labour, but here in north Cornwall Labour never stand a chance of taking the seat. I could shut my eyes and vote Labour as a matter of principle. Or I can decide to vote Lib Dem in the hope of keeping the Tories out. The thing is, in a democracy, that should be my decision, unhindered by anyone else telling me how to vote for whatever reason, including tactically. I don't want to be told that a vote for Labour is a wasted vote, or that if I vote Labour it will let the Tories in. In a democracy, the ballot box is the final call. Trying to sway me one way or the other at the ballot box is improper unless you know that I've been apprised in detail of the policies of all sides. After all, good democracy depends on a knowledgable electorate making informed choices.

As it happens, I vote for the Lib Dems here every time. I don't want the Tories in, so I vote and hold my nose. But if a LibDem candidate told me to vote for them in order to keep the Tories out, I'd very rapidly tell them where to shove it.