People haven't read the question. It's not the alt-right vs the far left, it's simply the religious right wing vs the far left. As I said before:
The premise of this question is inane. Being a religious right winger is not inherently an objectively wrong stance like racism, sexism, etc. While being regressive, regardless of your political party, is a factually undesirable trait.
This topic makes no more sense than asking "who is worse, radical Islamists or leftist atheists?." Implying that a standard left-wing atheist is equatable to a radical Islamist is both bigoted, insulting and incorrect, as it is to imply that being a regressive leftist is comparable to being a religious right winger.