Callista Gingrich, wife of former House Speaker Newt Gingrich, speaks at an event with Republican supporters at a Smashburger restaurant in San Diego on Tuesday. (Gregory Bull/AP)

Surrounded by the clean plastic surfaces of a fast-food burger joint, Callista Gingrich took on a new role in her husband’s presidential campaign here Tuesday: She spoke publicly to a small group of Republican women.

Yet even before she said a word, the woman who introduced Gingrich hinted at a subject the campaign usually avoids.

Lynn Ann Reagan-Jamison, president of a Republican women’s group in San Diego, described how Newt Gingrich and Callista Bisek met when he was the House minority whip and she was an intern for another congressman. “Fate,” she said, kept Bisek from attending journalism school and instead directed her toward her future husband.

What the introduction did not include was this delicate detail: Newt Gingrich was married to his second wife at the time; Bisek was in her late 20s and Gingrich in his early 50s. Their affair lasted seven years. And its memory lives on today, an unspoken liability that makes the Gingrich campaign handlers nervous and perhaps explains Callista Gingrich’s reticence until now.

With the Gingrich campaign at a crossroads, the candidate’s wife is finally starting to emerge, slowly, as a public figure in her own right. It may be a peculiar moment to do so: Her husband is struggling to regain momentum after a string of losses since his single victory, in South Carolina. The latest polls cast the Republican nominating contest as a two-man race between Mitt Romney and Rick Santorum. Aides say they have pressed Callista Gingrich to take a more public role for months, and she has long promised to do so. Ultimately, the timing has less to do with strategy than with Callista Gingrich’s readiness, they said.

When she did speak, Callista Gingrich said little, reading her remarks from a typed sheet while following the large, spaced words with her ruby-painted index finger. Her sculpted blond hair, bright-blue suit and gold-and-diamond necklace reinforced her carefully crafted look as a political wife. “Over the last few months, the campaign has been wild,” she told the Republican women. “We’ve been on a real roller-coaster ride, as front-runners seem to come and go.”

Her voice was soft, and she repeated phrases invoked regularly by her husband — that this is “the most important election of our lifetime,” that America “is at a crossroads.” She greeted women for about half an hour, posed for pictures and signed autographs with the fat-tipped blue Sharpie she makes an aide carry at all times.

Still, even her brief appearance and canned remarks were a revelation. By being silent for so many months, Callista Gingrich has only fueled a public fascination with her. Most of the time, she stands quietly behind her husband as he holds forth, her unmoving flaxen hair framing her stiff, smiling face. Where Ann Romney has taken to introducing her husband on election nights, Callista Gingrich’s voice is unfamiliar to most Americans.

The question for her now is whether a higher profile will help her husband’s cause or merely increase the demand for more answers about the early stages of their relationship.

“This was her first time as a spouse of a candidate,” said Gingrich spokesman R.C. Hammond. “For all intents and purposes, she has been doing this since May. She was getting used to the role.”

Even Newt Gingrich has left his wife’s role largely up to her. Asked whether the public would see more of her this week, the former House speaker said with a smile: “Apparently. Yes, I think the correct answer is yes.”

The women who came out to see Callista Gingrich on Tuesday praised her warmth and willingness to take the time to meet them. While some said enough has been said about how the Gingriches met, others said she waited too long to introduce herself to the public.

“She probably should have done this sooner,” said Reagan-Jamison, referring to Callista Gingrich’s decision to speak publicly. “She’s very articulate and very intelligent. I think most people know how they met, and they really want to move on.”

“I don’t know her very well, but in my short meeting with her she was a warm and true person, and I think people are just not going to get the right view of her until they do get to know her,” said Susan Skoglund, an officer with a La Jolla Republican women’s group. “She really does need to get out there and just show who she is.”

Callista Gingrich brushed past the question of why she decided to enter this more public phase now. “I enjoy meeting people,” she told a small group of reporters. “I enjoy speaking. This is a good time to do it.”

Her answer belied the intensity of interest in her: Callista Gingrich is the candidate’s spouse most often searched on Google, and supporters regularly ask her husband about her. During a Hispanic leadership event in South El Monte on Monday night, one voter asked: “What are you going to do for your beautiful wife tomorrow on Valentine’s Day?”

Gingrich replied, “All I can promise you is that I believe she will be quite happy after tomorrow night,” prompting the crowd to hoot and holler.

Blushing deeply, the candidate recovered with: “We will have a quiet dinner and exchange gifts and hopefully reconnect. No more details!”

“Any woman who we’re looking at as a potential president’s wife, they need to show who they are and not just kind of stand there,” said Skoglund, the La Jolla Republican. “She might need to say a few words on it herself and kind of explain her thoughts on it and then get past it. All wives need to show that they’re persons, too, with real thoughts, that they’re not just somebody standing there.”