If self-interested people want to show that they are independent, their best strategy is to be politically incorrect, and to proclaim loudly that's what they are being. The trick is that this strategy has nothing at all to do with genuine independence; it's just a matter of salesmanship, a way to get more popular.
If a politician makes some outrageous statement, and follows it with a suggestion that he deplores political correctness, you might well conclude that you can trust what he says. Whatever else they are, those who make outrageous statements seem honest and real rather than programmed or scripted. That's what a lot of voters are demanding.
But there is a sham here, and it's ironic. The very Republicans who proclaim their rejection of political correctness have committed themselves to a host of policy judgments that are, in their circles, politically correct. Those judgments help define the prevailing orthodoxy. If you want to survive, you had better not question any of them.