It's not just the left, it's the main demand of BLM, it's on their web page. If you don't agree, you're going to be labeled.
This is a misconception. “Abolish the police” refers to dismantling the current police department and starting over. All are fired and have to reapply. It was already done in Camden, NJ when it was deemed their police department was too corrupt to be salvageable. It does not mean “police should not exist.”