This is partly true, but incomplete.
What extremely liberal people openly admit to me, is that the have intolerance for people who are intolerant towards others on the grounds of race, non-discriminatory religious practice, gender, gender identity, sexual orientation, and perhaps some other categories.
So they are not anti-Christian per se, but are vehemently opposed to Christians who discriminate against people who identify as gay.
Antifa, or the leftist equivalent of the Alt Right, is probably the most visible manifestation these ideas.
And yes, members of the Antifa and their sympathizer are filled with the same kind of rage as the Alt Righters.
I actually think that people, particularly younger adults, get some kind of high or adrenaline surge from Antifa and Alt Right ideas. It's like snorting lines of cocaine, except the coke comes in the form of postings on Reddit or outrage pieces on Breitbart or Huffington Post.