Republican presidential candidate former U.S. Speaker of the House Newt Gingrich compared himself to five past presidents over the course of Thursday night’s debate. (POOL/REUTERS)

In the final Republican debate before the Iowa caucus, Newt Gingrich compared himself to no less than five different past presidents. “Just like Jefferson, Jackson, Lincoln and FDR, I would be prepared to take on the judiciary,” Gingrich said. And just like conservative icon Ronald Reagan, Gingrich said, who defeated president Jimmy Carter because people saw that “he believes what he’s talking about” and “has big solutions,” the former Speaker believes “I can debate Barack Obama, and I think in seven three-hour debates, Barack Obama will not have a leg to stand on.”

Such comparisons were hardly the first time Gingrich has ranked himself among well-known leaders of the past. Because he is “much like” former British Prime Minister Margaret Thatcher, he told CNN, “I'm such an unconventional political figure that you really need to design a unique campaign that fits the way I operate and what I'm trying to do.” The former history professor likes to compare himself to everyone from 19th century House Speaker Henry Clay (“I think Henry Clay's probably the only other speaker to have been a national leader and a speaker of the House simultaneously”) to Ho Chi Minh (“not in ideology, of course, but in commitment and fervor,” wrote Richard Reeves back in 1995 after Gingrich told him that like the communist revolutionary, “they can crush me. But they can't outlast me”).

That is only the start of it. He’s boasted recently that he helped invent supply-side economics, aided in the defeat of communism, and is running a campaign so revolutionary and successful that “it’s like watching [Sam] Walton or [Ray] Kroc develop Walmart and McDonald’s.” He has called himself “the most seriously professorial politician since Woodrow Wilson,” even if Gingrich never made tenure at West Georgia College, whereas Wilson served as president of Princeton. Slate’s Jacob Weisberg has a rundown of some of Gingrich’s older zingers, such as when he told The Washington Post back in 1985 that “I have an enormous personal ambition. I want to shift the entire planet. And I’m doing it.”

Humble, he is not. Gingrich’s fondness for positioning himself as a great mind surely speaks well to some, from his surging number of fans to these Fox hosts who said in reviewing Thursday’s debate that Gingrich “was historical, he was accurate, he was brilliant.” But others—even Republicans—think Gingrich’s self-importance is a big cause for concern. In a scathing editorial published in conservative bible The National Review Wednesday, Gingrich was called out for “his grandiosity”—one of his many character flaws that concern the magazine’s editors.

To some extent, anyone who decides to run for president is a narcissist. Somewhere in the back of his or her mind they must imagine they have the capacity to make a mark on history and the aspirations to change the world. Otherwise, why subject oneself to the brutal costs, both financial and personal, of trying for the most difficult job in the world? Even your average leader who does nothing approaching running for president tends to have an above-average level of self-confidence, ambition and tenacity.

At the same time, the best leaders mix that natural assuredness with a heavy dose of humility. We know this inherently, of course: The best leaders give credit to their teams and try not to overstate their importance. But study after study has also shown that more humble leaders are more effective and can foster better information sharing, even if big egos sometimes lead to better business performance.

Gingrich might think of himself as the savior to Western civilization, yet saying so—repeatedly—is a disturbing trait for any leader. Or any so-called historian, for that matter. As New York University history professor Jonathan Zimmerman wrote in the Chicago Tribune recently, when Gingrich left academia for Congress, “he also left behind the most basic canons of our discipline: rigor and humility. Put simply, [historians are] supposed to know what we're talking about. And when we don't, we're supposed to say so.” The line between self-confidence and self-glorification is a fine one. But it’s a very dangerous one for leaders, too.

View Photo Gallery: Leadership experts share their picks with us for top leader of the year, from Hillary Clinton to Tim Tebow.

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A leadership case for Newt Gingrich

Gingrich: More like Wilson than Roosevelt

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