There was a time when it was great to be a Republican governor. Governors became presidents. (In fact, 42 percent of American presidents have served as governor of a state.) Things have changed. Today, being a governor seems like an obstacle, not a fast-track, to the White House.

Indeed, the first two candidates to exit the Republican presidential primary are successful Republican governors. Rick Perry, the esteemed former governor of Texas, is out. Scott Walker, the governor of Wisconsin, who fought the unions on their own turf and won, is out, too. Many of the remaining governors and former governors in the race — Jeb Bush, Bobby Jindal, Chris Christie, George Pataki — are struggling mightily. Meanwhile, a celebrity carnival barker leads the field, followed by a former CEO and a retired neurosurgeon.

Walker was supposed to be the party's saving grace — the guy who could unite the GOP establishment, the tea party, evangelicals. He had a great Horatio Alger-style story. He seemed real.

And then he totally failed.

What both Perry and Walker lacked was experience on the national stage — the kind of experience that senators (and celebrities like Donald Trump) often have in spades. And in Walker's case, he clearly was not ready for primetime — his performance was very reminiscent of Perry 2012 — botching answers on foreign policy and disappearing from the debate stage.

In some respects, it's impossible to expect someone like Walker to be completely and immediately up to speed on foreign policy, monetary policy, and other issues of national and international import. The learning curve is steep. This is a guy who basically went directly from being a county supervisor to having to win three statewide elections in four years. In between he won a major battle against labor unions. Good luck finding time to "cram" on foreign policy.

That's the part I can forgive Walker for. The thing that really soured me on him, however, was the very transparent way that his team decided Iowa was "must win," telegraphed it, and then proceeded to pander to the populist right that presumably constitutes the base of the Iowa caucuses. It began when Walker ousted strategist Liz Mair for having said some uncharitable things about the state, but really manifested itself in the hurling of uncharacteristic red meat.

He flip-flopped on immigration, going so far as to say that it wasn't a flip-flop since he didn't vote on it. Then he went over the top on saying that he wanted a Constitutional amendment to let states ban gay marriage — but then (apparently) sent his wife out to let it be known that she disagreed. He started to look like a phony who would do or say whatever it took to be elected.

And then, having betrayed anyone not on the populist right (which includes center-right opinion leaders, establishment RINOS, and everyone in between), and having doubled down on being Iowa's hard-right populist, Walker was completely out-flanked by Donald Trump (and Ben Carson and Carly Fiorina and Ted Cruz). But mostly Donald Trump. Walker looked like a wimp on the debate stage. He had no charisma. He didn't look like a president. He didn't even look like a bully, as Trump does. He looked like the guy whose lunch money the bully takes.

The whole thing blew up in his face. Walker went all in on Iowa — and quickly plummeted from first place to 10th in the Hawkeye State. His donors panicked.

Is it any wonder America sent him packing?