No they haven’t. A small segment of “leftists” have, but as G2 points out assigning allegiance is complicated. Most people on all sides of the issue recognize that Hamas is terrible. Some of those also think Israel represses Palestinians and don’t like US tax dollars supplying bombs dropped on Gaza. It is possible to understand the problem Israel faces and also hope they can limit civilian casualties in fighting Hamas. There’s no easy answer and calling people names or assigning viewpoints to vaguely defined groups doesn’t do anything to fix problems. Sure, there are extremists that do defend Hamas, want to kill Biden, or other horrible things. But they are relatively few, hardly representative of the left.