Former senator Jim Webb of Virginia prepares to speak at Iowa Democratic Party dinner in July. (Melina Mara/The Washington Post)

If there’s a chance for a wild card on the stage at Tuesday’s lead-off Democratic debate, the smart money’s on former senator Jim Webb of Virginia.

Running an unconventional presidential campaign with little ground support, advertising or even public appearances, Webb somehow manages to march on. And with an eclectic set of views that defy categorization, he has a chance to draw attention and find, or repel, a new audience Tuesday in Las Vegas.

A one-term senator from Virginia, secretary of the Navy under President Ronald Reagan and a Vietnam War veteran, Webb falls both to the left and right of former first lady, senator and secretary of state Hillary Rodham Clinton. Like Sen. Bernie Sanders (I-Vt.), he was an early opponent of the war in Iraq. Long before Black Lives Matter protesters demanded attention from the Democratic candidates, Webb was working on criminal justice reform in the Senate.

Yet Webb holds conservative leanings as well. He opposes President Obama’s nuclear deal with Iran. After a white supremacist massacred nine black churchgoers in South Carolina, he called the symbolism of the Confederate flag “complicated.” He speaks often of low-income white men as ignored and disparaged by the Democratic Party.

His idiosyncratic views have not gotten traction so far. He polls in the low single digits both nationally and in the early-voting states of Iowa and New Hampshire. Unlike former Maryland governor Martin O’Malley, he has not built a large campaign or tried aggressively to challenge front-runners Clinton or Sanders.

Here's a look at one of the lesser-known Democratic presidential candidates. (Osman Malik and Sarah Parnass/The Washington Post)

Democratic strategist Joe Trippi said that reservation could be helpful in a debate. Republicans Ben Carson and Carly Fiorina, he noted, surged in polls after debates during which they bypassed other candidates’ bickering.

Trippi warned that too-harsh attacks are a mistake.

“Anything that comes off as an attack will backfire,” Trippi said. “It’s a huge opportunity, but in the drive to make sure you score, you get people’s attention in that first debate, you can overplay and sort of overreach.”

Like Carson and Fiorina, Webb is not a traditional politician. He left the Senate after one term. He likes to remind voters that he goes in and out of public service.

“He hates politics,” said Dave “Mudcat” Saunders, a longtime friend and adviser to Webb. “He’s a Renaissance man.”

In an atmosphere where establishment politicians are despised on both sides of the aisle, Webb’s genuine rebelliousness could be an asset. Yet voters also want to be courted, and Webb appears to have done little wooing in the early states.

“What in the world is Jim Webb up to?” a recent Boston Globe headline read. He missed a recent candidate forum in New Hampshire and a Democratic National Committee event in Minneapolis; he was the last to confirm his attendance at a high-profile Democratic dinner in Iowa.

Steve Jarding, who worked on Webb’s successful 2006 Senate campaign, in which he defeated incumbent Republican George Allen, said the candidate likewise views debates as “a necessary evil.”

Webb has prepared for debates in the past, Jarding said, but “he did not have a sense of urgency. . . . Jim’s attitude was just, ‘Let’s have it and see where the chips fall.’ ”

That perspective was a “double-edged sword,” in Jarding’s view. Webb would always stay calm, which was helpful, but he also would not take debate strategy as seriously as his campaign might have liked.

Webb often answers questions by referring to his writing. A week before he announced his campaign, he published not a policy paper, but a short story about Vietnam.

“He will bring back the words he’s carefully crafted,” recalled Allen, the former Virginia governor and senator who lost to Webb in 2006.

Although he considers Webb a liberal, Allen said his demeanor might not appeal to the Democratic base.

“He’s not one who’s flamboyant — you see his military bearing and sometimes he can seem a bit taciturn,” Allen said. “With his military leadership, he can give the impression to viewers or listeners or readers of a moderate conservative.”

Harris Miller, who was defeated by Webb in the primary that year, said Webb’s bearing and literary bent can come off as stiff.

“Jim’s very smart, he’s very articulate, but he’s also incredibly certain and the certainty can start to sounds like lecturing, almost like he’s your high school science teacher trying to help you understand what a molecule is,” Miller said.

At the same time, he added, “he will engage if he can; he’s not afraid to mess it up with anybody. He’s not going to sit there and take the idea that all Democrats are friends.”

Webb and Miller got in several testy exchanges in 2006. In one post-debate news conference, Webb told Miller to “shut your mouth.”

Jarding agreed that Webb is unafraid to take on a fellow Democrat.

“His instincts are pretty good,” Jarding said. [But] if people are expecting him to go wild against Hillary or Bernie, I wouldn’t bet on it.”

Webb’s campaign declined to discuss strategy for the debate or for the primary campaign in general.

“We have the best candidate to deliver economic fairness, social justice and common sense foreign policy, unbought and unbossed by anyone,” said Webb spokesman Craig Crawford.