For all his supposed authenticity, Rick Santorum is not what he seems. Beneath that sweater vest beats the heart of a calculating and increasingly desperate politician who has gone beyond pandering all the way to shameless demagoguery.

That’s the charitable view. The uncharitable take on Santorum’s incendiary rhetoric is that he actually believes this stuff. Either way, it’s time for Republican voters to end his little electoral adventure and send him back to the cosseted life of a Washington influence-peddler.

The image of aw-shucks earnestness that improbably landed Santorum in the Republican Party’s Final Four was beginning to fade. Mitt Romney, who is nothing if not relentless, was beginning to climb back up in the polls, and Santorum risked becoming nothing more than the latest of a series of anti-Romneys to bite the dust. Something had to change — so, in recent days, Santorum’s avuncular smile has become a nasty sneer.

On Saturday, he attacked President Obama for advocating higher education. Yes, you read that right: Santorum came out against going to college.

“President Obama once said he wants everybody in America to go to college,” Santorum said in Michigan. “What a snob.

Huh? Santorum elaborated: “There are good, decent men and women who go out and work hard every day, and put their skills to test, that aren’t taught by some liberal college professor trying to indoctrinate them. Oh, I understand why he [Obama] wants you to go to college. He wants to remake you in his image.”

Ridiculous? Offensive? Hypocritical? Manifestly, all of the above.

Only a fool or a liar is unaware that higher education is all but a prerequisite for success in the post-industrial economy; the unemployment rate for college graduates is just 4.4 percent, compared to 9.5 percent for high-school graduates. The idea that encouraging young people to go to college is really an attempt to lure them into indoctrination camps, or campuses, would be grossly insulting if it were not so comically paranoid.

But of course Rick Santorum doesn’t practice what he preaches. He went to college and holds both a law degree and an MBA. He’s sending his own children to college; his two eldest, Elizabeth and John, are interrupting their studies to help their father in his campaign.

Santorum told ABC’s George Stephanopoulos on Sunday that “there are a lot of people in this country that have no desire or no aspiration to go to college, because they have a different set of skills and desires and dreams that don’t include college.” Yet he makes sure his sons and daughters are not among them.

Hypocrisy and illusion are nothing new for Santorum. He plays up his alleged blue-collar roots, contrasting himself with the snooty Romney. But his father, Aldo Santorum, was a clinical psychologist who held graduate degrees, including a Ph.D., and worked for the Veterans Administration. His mother was an administrative nurse.

Wait, there’s more. Stephanopoulos also asked Santorum about something even more ridiculous that he said last October: that he “almost threw up” when he read John F. Kennedy’s famous 1960 speech about the separation of church and state.

That landmark speech was credited with reassuring voters who might have feared that Kennedy, a Catholic, would somehow take orders from the Vatican if he were elected president. “I believe in an America where the separation of church and state is absolute,” Kennedy said.

Santorum’s view is the polar opposite. “I don’t believe in an America where the separation of church and state is absolute,” he said. He claims Kennedy was proposing that “only people of non-faith can come into the public square and make their case” — which is not even remotely what Kennedy said. The speech was a celebration of religious pluralism, not an argument against faith.

I have to assume that Santorum knows what Kennedy meant — that when he says “the idea that the church can have no influence or no involvement in the operation of the state is absolutely antithetical to the objectives and vision of our country,” he’s just trying to appeal to religious conservatives. If Santorum is serious, his views are not just misguided but dangerous.

Progressives have an obvious interest in seeing the Republican Party choose a weak nominee, but they shouldn’t hope for Santorum. He would be the most extreme candidate since Barry Goldwater — and probably would suffer the same fate. But the nation can’t afford to take that chance.