Back when I first started paying attention to politics, Joe Klein types would paint this picture of the Democratic party as some hodge podge of identity politics groups each demanding unquestioning fealty to its ideological demands. How this was squared with the Democratic party of TipAndRonnieGoOutforDrinks I really have no idea, but that was how the press talked about it. You know, it's how we get recyled bullshit THE DEMOCRATIC PARTY WOULDN'T LET BOB CASEY SPEAK AT THE CONVENTION BECAUSE HE WAS ANTI-CHOICE stories decades later. That THE LEFT demands complete ideological purity has been an article of faith for as long as I can remember.
But it is increasingly true of the Right, that there is a growing list of views and beliefs which one must adhere to.