Newt and Callista Gingrich take their marriage on the road

MOUNT VERNON, Va. -- It wasn't just any author signing her book during weekend Christmas festivities at George Washington's historic estate along the Potomac River. It was Callista Gingrich and her husband, who would very much like to have Washington's job.

A thousand miles away in Iowa, their rivals in the GOP primary field were busily launching attacks on Newt ahead of the state's critical Jan. 3 caucuses. He and his wife Callista, meanwhile, spent two hours signing copies of Sweet Land of Liberty--her illustrated children's book--beside Ellis the Elephant, a human dressed as the story's main character.

When the political world lit up with news that the Des Moines Register had endorsed Mitt Romney, Newt Gingrich was singing carols and listening to his wife play the French horn with the City of Fairfax Band at a Christmas concert sponsored in part by the Gingrich Foundation that she heads. Then they walked hand-in-hand to their car.

Gingrich's third wife is widely known as the much younger former mistress who carried on a six-year affair with the married Gingrich, part of it while he was leading impeachment proceedings against President Bill Clinton for charges stemming from Clinton's own adulterous affair. Team Gingrich is betting that it can replace that image with another, of a functional modern marriage and mutual devotion.

The couple flashed bright smiles and posed side by side for the cameras Saturday at Mount Vernon. They warmly shook hundreds of hands and made small talk with shoppers and tourists, most of whom were visiting the historic home for other reasons when they happened to spot the Gingriches. Newt even got to explain his old job--speaker of the House--to 10-year-old Will Maloney of Dumfries, Va.

Diane Luicana, 50, a Republican-leaning visitor from Pottstown, Pa., was impressed. "It shows him as a whole package to be there with his beautiful, sweet wife. She shows his human side," said Luicana, who picked up a copy of the book for her infant niece. "They should keep her with him all the time!"

Though Callista is the most visible symbol of Newt's personal baggage, the campaign has made no effort to shunt her out of the spotlight. She's a prominent part of the operation and a constant presence on the trail. She has been appearing solo for the past several months to deliver a speech on American exceptionalism and to do book signings.

Yet she continues to remain something of a mystery. When she campaigns with her husband, she rarely speaks. When she sits down for an infrequent interview on her own, she doesn't reveal any soul-baring details.

"We are a team and we spend a lot of time together. This was a joint decision that he would run for the presidency and I'm glad we made that decision," Callista said in a recent interview with the Christian Broadcasting Network.

That was about as intimate as it got.

Newt regularly sings Callista's praises unprompted in interviews and other appearances. He credits her with changing him for the better and for reaffirming his faith--he converted to Catholicism, her religion, in 2009.

Full CBS News coverage: Newt Gingrich

"We campaign together and we like, we just like hanging out together so we are a team," Gingrich said in November at the opening of his South Carolina headquarters. "Proudly, Nancy and Ronnie Reagan are the closest analogy that I know of in terms of how we work together and try to do things together."

Reactions from some shoppers at Mount Vernon suggest the Gingriches may be onto something. One man said the Newt Gingrich at the signing was different from press reports of a surly and overconfident politician. Another visitor, Robin Porath, 49, of Broad Run, Va., who was at Mount Vernon for a holiday party, called the couple "very personable." Callista "didn't seem canned at all," she added.

Dean and Kristine Bryant, who were buying Christmas ornaments on Saturday and stopped to get their books autographed for kicks, typify Virginia's closely divided political climate--she is a Republican and he is a Democrat. Though they can't talk politics at the family dinner table, they agreed that it's not realistic to expect elected officials to be blemish-free.

"I don't know if I can hold it against someone that they've been married three times," Kristine Bryant said. "That's not how I'm going to hinge my vote."

"It comes down to an issue of character, but everyone's got skeletons in their closet," Dean Bryant chimed in.

By Sunday, Newt was back in political combat mode on CBS's Face The Nation. The good news from Saturday: The Mount Vernon gift shop sold out of its 200 or so copies of Sweet Land of Liberty. And if Gingrich becomes the GOP nominee, it won't hurt to have left a positive impression with some prospective voters in a state that will be pivotal to deciding the next president.

Gingrich on Face the Nation:

Gingrich: Gov't branches should rule 2 out of 3
Gingrich: We "earned" criticism over Freddie Mac
Gingrich: U.S. created a vacuum in Iraq
Gingrich: Voters like my "positive" message