Comment by dmurray
5 years ago
Outside the US, I hear "looney left" and related terms used all the time by political moderates to describe any leftist groups outside the political mainstream, with a similar connotation to "alt-right", though it's a meaner phrase. It's derogatory towards them, but not towards the left in general.
Inside the US, "looney left", "communists", and "traitors" are all used by the political center-right and right-wards to describe any leftist group. Any reference to the left is intended to be derogatory.