Romney takes pride in not being a career politician, a boast that evoked one of Gingrich's few illuminating retorts: "Let's be candid, the only reason you didn't become a career politician is you lost to Teddy Kennedy in 1994." If going into politics to create jobs is justified, why isn't it commendable to spend a career in politics to create jobs?
He extols his record of building businesses and creating jobs in the private sector. If he's so good at that, though, why not stay there?
We know why most candidates undertake the race -- Al Gore to avert environmental catastrophe, George W. Bush to carry on the family business, John McCain to serve his country and Obama to heal racial and ideological divisions.
Romney just seems like a rich guy who needs a new challenge. "I have a good life with my family, my wife," he says. "I don't have to win. I just want to win because I care about the country."
Ronald Reagan could have said the same thing, but with him it was believable. Reagan was driven by a distinct vision of what America should be. Romney, by contrast, is willing to serve whatever cause will get him elected.
His attitude is: Tell me what you want me to be and I'll be it. But one thing voters want is someone who doesn't do that.
About Gingrich's motive, there has never been any doubt: to feed an insatiable ego that makes him imagine he has a historic, God-given mission to transform the country. He's a mad scientist, mixing volatile potions that may cure cancer or may blow up the lab. Either way, he'll have fun.
Romney doesn't have an obvious reason to run for president. That's his trouble. Gingrich does. That's his.