Which presidential candidate served as secretary of the Navy under Ronald Reagan, championed prison reform and referred to his campaign as "insurgent?"

Former Virginia senator Jim Webb.

Webb is one of the three lesser-known Democratic candidates who will take the stage beside former secretary of State Hillary Clinton and Sen. Bernie Sanders (I-Vt.) at Tuesday's presidential debate.

Watch this video to see what you need to know about Webb in 30 seconds or less.

The former senator is known for urging prison reform, opposing the Iraq war and criticizing the nuclear deal with Iran.

Having served just one term in the Senate, Webb says he's not  "a career politician." When he announced his bid for president in July, he announced his intention to "clean out the manure-filled stables of a political system that has become characterized by greed."

Two months into the race, Webb called his campaign "under-financed" in a message to supporters. But he emphasized that the time was "right" for him to break into the competition against Clinton and Sanders.

On Tuesday night he might have a chance to do just that.

Webb has garnered more Internet search interest from Americans than rival rival candidate Lincoln Chafee, but he falls short of the interest in Sanders and Clinton.

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