I don't think all or even most realize at all. They are like religious fanatics indoctrinated and parroting what they were programmed with. I also suspect many are puppets to their masters who indoctrinated them even decades post graduation.  A little button pushed here or there and they spout out the new and improved dogma.  Kind of how I suspect Operation Mockingbird really works. Like a telephone tree except using other methods perhaps. The majority lying to us on tv and print are just doing what they were programmed to do when they get told today's keywords and tag lines.  Yesterday, aa Tucker Carlson pointed out very well, it was a pivot from 2 years of Russian Collusion to nearly every one of them attacking Republicans on another "soon to fail" repeal of Obamacare