Among the hundreds of fans — and these days, there are always hundreds — who stood in line for hours to meet Newt Gingrich at a book signing, there was an older man gushing about watching the former House speaker on C-SPAN in 1980. Another fan brought a copy of the 1995 Time magazine Man of the Year cover for Gingrich to sign. Upon approaching him, a woman marveled at how little Gingrich had changed over the years and mused, “I always thought he’d make a good president.”

If there’s one thing that should be working against Gingrich at a time of anti-Washington fervor, it is his tumultuous decades in and out of power in the nation’s capital. Gingrich should be the has-been, the speaker who compromised, the career politician with a speckled past of ethical and personal transgressions.

But somehow, among Republican primary voters, Gingrich’s long history on the national stage has become an asset — and one that could enable him to have more staying power than a string of other candidates who have also had a shot to be the alternative to Mitt Romney, the front-runner.

Those others — Michele Bachmann, Rick Perry, Herman Cain — rose on their first impressions and fell at the first stumble. It’s not that Gingrich hasn’t dealt with many of the same problems they have confronted: a tainted personal life, positions out of step with the party, brash comments that angered other Republicans. It’s just that those things aren’t all that voters know about him.

Many Republican voters grew up with Gingrich. Wherever he travels, he is greeted by supporters who have followed him for decades. They have read his books, watched his documentaries, listened to his audio recordings. They are even comforted by the way he looks — same hair, unchanged face.

In a year when no one else seeking the GOP presidential nomination has won over the hearts of Republicans, voters at least have the sense that Gingrich has been right there with them, fighting the conservative cause all along.

“I equate Newt’s ability to turn things around to Ronald Reagan,” said Lyle Yoder, 80, a retired small-business owner who watched Gingrich on C-SPAN 30 years ago and remembers hearing him speak at his sister-in-law’s 1991 graduation from Liberty University. “His commencement speech, he gave it the same way he speaks now. He has no fear. He exudes confidence. And he did all those years ago, too.”

Many voters said they withheld their support for Gingrich until now because they weren’t sure that his campaign was viable after his staff quit in June and money dried up. But as the Romney challengers who preceded him struggled to demonstrate their knowledge and readiness for the job, there Gingrich stood, performing solidly in debates and delivering a well-honed story line.

“I always knew that Newt was the smartest man on the stage,” said Diane Harris, 50, who works in the travel industry and lives in Naples. “I just questioned whether he had the ‘it’ factor. But after listening to him answer questions, I wish the whole country could have been here today.”

Gingrich has surged to the top of polls alongside Romney in recent weeks, primarily because of the support of people like Harris — older, more conservative Republicans. In a Washington Post-ABC News poll released this month, Gingrich’s approval rating among those 50 and older was 71 percent, compared with 45 percent for voters younger than 50. And his approval rating among very conservative voters was 67 percent, compared with 44 percent among moderate-to-liberal Republicans.

On the campaign trail, Gingrich weaves his knowledge of the Capitol and the federal bureaucracy with a series of anti-Washington zingers, portraying himself as both an outsider appalled by the ineffectiveness of the government and the man best positioned to make change. He takes credit for challenging his party’s leadership in his early years in Congress and for battling President Bill Clinton over his four years as speaker — but also for bringing dozens of Democrats on board to enact sweeping welfare reform. By his own account, he is both a hard-liner against Washington and an eminently reasonable and successful tactician.

That combination, he says, allows him not only to win the hearts of conservative primary voters — notably tea partyers, who have helped beef up his organizations in the early-voting states — but also to make the case that he can go up against President Obama in the fall.

“Most of our lives we’ve never seen the House and the Senate so ineffectual, at total odds, which totally leaves the American people out of the process,” Gingrich told an audience of more than 800 supporters jammed into a hotel ballroom last week. “We’re watching total insanity go on. We could begin to break up the gridlock very rapidly if I were president.”

Gingrich draws on his experience to fend off controversy, too, including his statement at a debate last week that he favors creating a path to legal residency for some illegal immigrants.

Answering charges over the weekend from Bachmann and Romney that his position would lead to amnesty, Gingrich said: “I have a deep history, going back to 1986, of supporting efforts to solve the problem of illegal immigration.”

He said in an interview that the depth of familiarity of so many of his supporters is “sobering.” He also attributed it to a nugget of political trivia that helped launch his national career: the start of C-SPAN, in March 1979, just two months after he entered the House. Gingrich was a regular guest, and he quickly understood — and began taking advantage of — the power of live broadcasts from the House chamber.

Gingrich also got people’s attention through audio tapes he recorded when he was chairman of GOPAC, a Republican political action committee that he used in the late 1980s and early ’90s to train Republicans across the country seeking political office. His recordings — along with workbooks, seminars and other educational tools — detailed the party’s message and how to organize at the grass-roots level.

Along the way, Gingrich created an endless number of memories for political supporters. Dorothy Nichols, 78, a homemaker from Bonita, Fla., said he spoke to her son’s war college class a dozen years ago — and individually critiqued each student’s work. “We were so impressed with Gingrich, it made us follow him all the way,” she recalled.

Dan Seufferlein, a lawyer in eastern Iowa, remembers the night, in November 1994, when the Republicans took over the House. He was 19 and working at a grocery store, and he was reprimanded for repeating to customers and co-workers alike: “Newt Gingrich is going to be speaker! Newt Gingrich is going to be speaker!”

Today, Seufferlein is volunteering for Gingrich's presidential campaign. “He’s just kind of an iconic figure for me,” he said. “He’s been involved in the discussion of politics for such a long time. And he was at the height of that when I became politically aware.”