This is a rare form of leadership, especially among politicians. For one thing, it was a feat of strength. Second, it was in many ways an act of solitude. According to the Legislative Reference Library of Texas, someone who filibusters may not lean on anything, including colleagues. In fact, Davis had planned to stand for 13 hours, but the state senate ruled that she had broken filibuster rules three times, one when Texas senator Rodney Ellis helped her adjust a back brace she had been wearing.

Leadership is often tied to the accomplishment of difficult feats. This is certainly a hallmark of military achievement. The United States Army has seven core values, one of which is personal courage. The Army describes it as follows: “Face fear, danger, or adversity (physical or moral). Personal courage has long been associated with our Army. With physical courage, it is a matter of enduring physical duress and at times risking personal safety.”

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When former NASA space shuttle commander Jeffrey Ashby wanted to hone his team’s skills pre-flight, with only months to prepare for the launch, he insisted they take a National Outdoor Leadership School trip to the southeastern canyon country in Utah. By the time the team flew to the International Space Station, they were used to working together under duress.

Ashby organized a team-building exercise in the desert and Davis’s filibuster was a lone act in the Texas Capitol building — but both acts demonstrate the central role of perseverance in leadership.

Perhaps a physically and mentally taxing filibuster is the closest a political debate ever comes to the stress of serving in the military or flying a spaceship.

“You remember the Jimmy Stewart movie?” asks Robert Kaplan, a management professor at Harvard Business School, referring to the classic Mr. Smith Goes to Washington. “Those filibusters always capture the imagination because they’re more visible than a vote, and they require hardship.”

Only people with deep convictions tend to endure difficult situations. In other words, you can’t fake your beliefs through a grueling exercise. “And when you see people do that, particularly a politician, people admire it,” Kaplan adds.

This kind of conviction is common, Kaplan says, which is why people relate to it. “This country, in my opinion, actually is full of people who are figuring out what they believe and acting on it. The reason people get dispirited is that you don’t see it as much in Washington.”

Typically, leadership in Washington happens behind the scenes. “It’s an old adage in Washington that you can get anything done if you don’t want to take credit for it, and it is true,” Princeton professor and former U.S. State Department director Anne-Marie Slaughter told Fortune. “It’s just the way the town tends to work.”

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But people saw something different in Texas’s Wendy Davis actions — even some of her opponents nodded to her conviction before questioning her on technicalities of the bill. By the time SB5 officially failed, at about 3 a.m. Texas time, the state capitol building in Austin was full of Davis’s supporters, cheering loudly.

Davis’s experience represents a common leadership tale: When you exhibit a strong sense of purpose by doing something difficult, even if you begin alone, others will follow.