"This implies that most don’t actually believe much of what they say for public consumption"

This may have been true at one time, and I think that it is still true to some extent in the Senate -- although probably less than we'd like to believe, as we'll find out when McConnell finally hangs it up -- but I'm afraid that in the House, the majority of them have been "faking it 'till they feel it" for so long that they actually DO feel it. Those who wouldn't or couldn't conform have been purged. The ones passing for "normies" don't have better views, just better manners.