Many don't and can't.
For instance, I actually am for abortion rights (at least to a certain point) but think the supreme court made the right call. As it stands, abortion is not addressed (enumerated) in the constitution, therefore it is a states issue, and needs to be fought for at the state level.
If the left genuinely believes it should be a federal issue, they need to draft and ratify a constitutional amendment. You know, follow the proper process.
