Back in 2012 when Donald Trump famously went in pursuit of President Barack Obama's birth certificate, he sounded as though he was pursuing a stray dog rather than the leader of the free world.

Being Trump, he brought along the world's press on his idiotic goose chase. At the time the subtext of his efforts could not have been clearer: Trump was suggesting that there was something unseemly about Obama amounting to fraud.

Trump was suggesting that Obama should not be entrusted with the awesome responsibilities of his job. He was suggesting Obama could actually be a foreign imposter, and possibly a liar.

With his blatant attempts to undermine the president’s authority, Trump's subtext was practically text: Barack Obama didn't look or sound like every previous American president, and that was reason enough to have serious reservations about him. It had nothing to do with the color of his skin; oh heavens no.

No one in the Republican Party leadership corrected Trump's approach at the time because they were as eager as he was to find a weakness in the president’s armor. They were all in search of a way to fatally damage his standing. That's how this “he's-really-not-one-of us” dog whistle approach was quietly approved.

It was a colossal mistake that is finally coming home to roost now, however. When you give entitled bullies latitude they will always take it. When you fail to call them to account they will assume your weakness, and they can even assume you approve.

Until these past few days, Trump has had every reason to think that the GOP that was behind his birth certificate buffoonery would back his race baiting of Mexican immigrants, because to date they invariably held their tongues and their noses while he pursued it.

Instead, though, news reports suggest Trump is deeply surprised his incendiary comments about Mexicans are turning him into an international political and corporate pariah.

His shock is understandable. For years he has had every reason to believe his views reflected the private thoughts of countless other rich old white guys like himself. After all, if everyone in your world sounds like everyone else in your world, you can come to believe that your opinion is the only one that's out there.

That's why Trump is shocked to find himself so alone on the stage. His supporters thought that poking fun at Obama's origins was funny, but calling Mexicans rapists and thieves, well, not so much.

Critics say Trump's inflammatory comments should see him shunned from the GOP primaries in the same way the corporations have bailed from his brands. He is unlikely to be shunned however. Party leaders will allow him to throw red meat to the base for as long as they think it’s useful.

Commenting on the furious backlash over his anti-immigrant comments, Trump told Fox & Friends, “I didn't know it was going to be quite this severe. But I really knew it was going to be bad.”

He's not a foolish man, but the truth is Trump may have overestimated the good faith of his conservative friends and the white hot hostility of his enemies.

“You know, maybe I'm leading in polls, but this is certainly not good,” he said. “I lose customers, I lose people.”

That's a fact. Since last week Macy's, NBC Universal, Univision and Serta have all dropped their partnerships and business dealings with Trump following his remarks which, wouldn't you know it, Fox News co-host Clayton Morris approvingly described as “straight talk.”

“For the people who say I'm doing it for my brand -- this isn't good for my brand. I think it's bad for my brand," Trump said.

Another brand it’s bad for is the GOP's. If you still think Trump's race baiting (since his birther days) isn't an unfolding disaster for the GOP in 2016, you really should start now.

If you went to central casting in search of an actor to play a bloated and out of touch plutocrat, you couldn't do any better than return with an effigy of Donald Trump. It's an image that the GOP may come to rue.

Donald Trump: Demonizing immigrants is the oldest political trick in the book, something generations of Irish suffered.