Donald Trump — after years of race baiting his way into the conservative movement — is now exploding like a big racist supernova in the GOP primary. His chances of winning the party’s nomination are slim but the fact that his anti-immigrant rhetoric has catapulted him to the top of the polls is a concern for the Republicans who actually take their party seriously. And Republicans should be concerned. Trump, as many have said, is the “id” of the Republican Party. He lays bare the subtext of a movement whose ideas and governance have been revealed as disasters again and again (except in places like Texas, where a combination of federal dollars and a global addiction to fossil fuels allowed the economy to steam along despite the financial crisis).