My response is very unpopular here.
Social issues are driven to the front of the debate by liberals because they are the Achilles' heel of today's right wing. People have an image of the GOP that's based on fights against SSM, etc.
The image of the right wing in general, which is the de facto image of the GOP in the minds of the sans culottes is that of a bunch of religious moralists who would impose Christian sharia on the nation, all of it controlled by powerful, mega-wealthy evil billionaire tax scofflaws who eat poor black baby omelettes for brunch at Trump's Lago Mar in Palm Beach. I don't for one minute believe that poor black baby omelettes are served at Lago Mar.
Liberals spend their time trying to force people into doing things they don't want to do, while conservatives spend an equal amount of time trying to stop people from doing things they want to do.