Twelve years after leaving Congress under a cloud, Newt Gingrich leads other possible GOP presidential candidates in many polls. The former House speaker has been in public life a long time, so most Americans know something about his politics; but, in a lengthy profile published in Esquire, writer John H. Richardson asks, "Just who is Newton Leroy Gingrich, really?" To uncover the answer, Richardson got Marianne Gingrich, the second of Gingrich's three wives, to sit down for a rare interview. Here are her 5 most shocking claims:

He began dating his math teacher at age 16:
It's widely known that Gingrich's first wife, Jackie, was once his high school geometry teacher. "To this day, the official story is that he started dating Jackie when he was 18 and she was 25," says Richardson. But, according to Marianne, "he was really just 16."

He cheated on his wife, then compared her to a car:
A few months after she had been diagnosed with multiple sclerosis, Marianne Gingrich confronted Newt, and he admitted he was having an affair (with Callista Bisek, then 32, a former Hill staffer who later became his third wife). The couple tried to talk through it, but Gingrich got stuck comparing his wife and lover to cars, saying Marianne was a Jaguar and all he wanted was a Chevrolet. "I can't handle a Jaguar right now," Gingrich said several times. "All I want is a Chevrolet."

"Family values" don't apply to him:
When Marianne confronted Newt about his cheating, he had just returned from a speech where he spoke of the importance of family values. Yet he asked her to simply tolerate the affair. She refused, and asked him how he could give high-minded speeches while simultaneously running around on his wife. "It doesn't matter what I do," he answered. "People need to hear what I have to say."

He borrowed jokes from his ex-wife:
Explaining how his current wife, Callista, is simultaneously younger but more mature than he is, Gingrich tells Richardson, "Callista and I kid that I'm 4 and she's 5, and therefore she gets to be in charge." When Marianne hears the anecdote, she's stunned. "You know where that line came from? Me. That's my line. That's what I told him," she says. She pauses, then says, "I'm sorry, that's so freaky."

"He's a sociopath, but he's our sociopath":
In 1997, after being fined $300,000 by the House Ethics Committee, "Gingrich started to deteriorate," Richardson writes. "He started yelling at people, which he'd never done before, and he'd get weirdly 'overfocused' on getting things done — manic, as if he was running out of time. He started taking meetings while eating, slurping his food, as if he weren't aware or didn't care how strange it looked. The staff responded with gallows humor: 'He's a sociopath, but he's our sociopath.'"

Sources: Esquire, Wash. Monthly, Newser, AlterNet, New York