Hello Caitlin,
What I know is that there are some fanatic Clinton supporters for who criticism of US imperialism and wars around the world is taboo because it would "play into the hands of Trump, far-right and authoritarians", and when other left-wingers dare to break this taboo, these latters are then harassed and threatened by those who accept only Atlanticist well-thinking and political correctness.
For me, these fools are not leftists, but rather radical centrists since they constantly put on the same level left politics and right politics while that left-wing and right-wing have very little in common. They usually campaign for progressive causes except when it's a question of denouncing this injunction to patriotism and unconditional allegiance to our authoritarian and warmongering leaders.
These fools only put sticks in the wheels to real left-wingers who form the greatest force against all forms of racism, sexism, fascism and xenophobia.