We unfortunately live in a two-party system. If these alienated voters are being forced to choose between the transphobe, or someone who wants to systematically eradicate trans people, I hope those alienated voters wisen the fuck up real quick.
At that point, their noble protest vote (or abstinence from voting) does nothing but make the world a worse place. Learn to fight for progress, instead of kneecapping everyone else from being able to do so because your candidate doesn't toe the line with literally every single one of your values.