It is because the left cannot abide by the Constitution.
The left does not believe in the Constitution, hence they cannot and will not abide.
I remember when, I think it was Al Gore got caught in involution of law and was never prosecuted for it.. And when asked about it he said, "There is no controlling legal authority.. That just about sums up the problem we, as a nation, are suffering at this time. We have no DOJ. and law breakers, big and small are getting away with it..
"Their mindless determination to confiscate guns by any means possible, either overt or devious, and censor speech they do not approve is unbound and unrestrained regardless of court rulings."