The defense of lesser evil politics is just heating up. It can become quite testy because it doesn’t just signify a different way of getting to the same goal; it represents entirely different approaches to politics & social transformation. It’s the reality of Robert Frost’s poetics that “Two roads diverged in a wood…& that has made all the difference.”
The primary difference is whether one looks to compromised, often corrupt politicians to create social change or whether one looks to organizing working people to achieve their own liberation from inequality. It’s where you place your trust & commitment in practice.
There can be no possible objection under democracy (though the rigged US electoral system is definitely not that) to people voting as they see fit, nor to justifying (or not) their choices. But do they have to explain away the rotten politics of their chosen candidates? You can choose Sanders or Clinton but you have to be honest that a lot of rightwing rubbish comes along in that choice. Or do war, Israeli apartheid, refugee rights mean nothing?