When former Michigan governor George Romney ran the American Motors Corp., did his son Mitt get an internship in the used-car department?

The back-slapping, fast-talking, never-stop-smiling style of Mitt Romney calls to mind the silky-smooth used-car salesman who will say or do anything to con you into buying what he’s hawking.

Now hold on, Romney devotees; that thought is not mine alone.

In March, U.S. News & World Report published a poll, conducted by Craigslist and IBOPE Zogby, that asked Republican voters whom they would trust more when buying a used car: Rick Santorum or Mitt Romney?

Of the 660 adults surveyed, U.S. News reported, six out of 10 Republicans said they trusted Santorum enough to buy a used car from him, while fewer than half said they would buy one from Romney.

The trust gap was higher among women. Nearly seven in 10 Republican women said they would buy a used car from Santorum. Fewer than half said the same for Romney.

Style alone does not account for Romney’s low score. His well-documented record of flip-flops on issues adds to the public’s distrust.

I believe, however, that it is Romney’s penchant for talking out of both sides of his mouth, his willingness to say different things to different people about the same subject, that is doing him in with voters.

There is no better example than his message to the NAACP in July and his remarks to fat cats at a private fundraiser in May.

Romney went to the NAACP, the nation’s oldest civil rights organization, and said that Barack Obama’s presidential victory in 2008 should have been the last door of opportunity African Americans would have to open. He continued: “Of course, it hasn’t happened quite that way. Many barriers remain. Old inequities persist. In some ways, the challenges are even more complicated than before.”

“If equal opportunity in America were an accomplished fact,” Romney told the gathering, “then a chronically bad economy would be equally bad for everyone. Instead, it’s worse for African Americans in almost every way.”

Thus spoke Romney, the Empathetic.

Next up, Romney, the Equal Opportunist.

“If equal opportunity in America were an accomplished fact,” Romney observed, “black families could send their sons and daughters to public schools that truly offer the hope of a better life. Instead, for generations, the African American community has been waiting and waiting for that promise to be kept.” Then he opened up:

“Our society sends [black children] into mediocre schools and expects them to perform with excellence, and that is not fair. . . . The path of inequality often leads to lost opportunity. College, graduate school, and first jobs should be milestones marking the passage from childhood to adulthood. But for too many disadvantaged young people, these goals seem unattainable — and their lives take a tragic turn.”

Then he gave them a strong dose of Romney, the Understanding:

“Many live in neighborhoods filled with violence and fear, and empty of opportunity. Their impatience for real change is understandable. They are entitled” — note his use of that word — “to feel that life in America should be better than this. They are told even now to wait for improvements in our economy and in our schools, but it seems to me that these Americans have waited long enough.”

Expressing anger at a system that sets children up for failure instead of preparing them for life, Romney told the largely African American audience: “Everyone in this room knows we owe them better than that.”

Acknowledging that he was speaking to a group whose members overwhelmingly vote Democratic, Romney declared: “We don’t count anybody out. . . . Support is asked for and earned, and that’s why I’m here today.”

So he spoke to the NAACP.

But a few weeks earlier, Romney had gone before the now-famous private gathering of rich donors at a $50,000-a-plate fundraiser in Boca Raton, Fla., and spoke out of the other side of his mouth.

Romney told his rich pals that people who are “with” Obama “are dependent upon government,” “believe that they are victims,” “believe the government has a responsibility to care for them,” “believe that they are entitled to health care, to food, to housing, to you-name-it. That’s an entitlement.”

Romney, of course, was slurring more than the members of the NAACP. He also insulted retirees, college students, Americans with disabilities and people who work for a living for not much pay.

No matter. Romney dismissed them all, telling his well-heeled donors, “My job is not to worry about those people. I’ll never convince them that they should take personal responsibility and care for their lives.”

Witness Romney, the Chameleon, telling that crowd what they wanted to hear.

No wonder fewer and fewer people are buying what he’s selling.