Editor’s note: This is the final profile on the four major candidates running for Louisiana governor.

On a recent Saturday night, David Vitter glided with ease through the crowd at St. Agnes Le Thi Thanh’s Vietnamese Fall Festival in Marrero.

“Hey, Mr. David,” a man called out, reaching out to shake the hand of the Republican candidate for governor and senior U.S. senator from Louisiana.

“Hope you win!” another yelled from across the table, giving Vitter a thumbs-up.

Festival attendees gathered for photos around Vitter, who was dressed down in jeans and a red plaid button-up, and he seemed to captivate the audience when he took the stage.

The gathering illustrated the type of die-hard support that Vitter, who has served in the Senate for the past decade following a five-year stint in the U.S. House, enjoys as he campaigns across the state for what he hopes will be his next — and final — elected office: Louisiana governor.

“I have great friends who support us,” Vitter said, his voice hoarse — typical for politicians during campaign season but probably exacerbated by his particularly packed schedule that day.

It was Vitter’s last stop on an Interstate 10 tour that had him in Lafayette, Breaux Bridge and Baton Rouge earlier in the day. It was also a rare Vitter campaign event with a reporter in tow.

“It’s nonstop,” he said between handshakes with eager supporters. “I’m doing absolutely everything I can today.”

Vitter has crammed much of his campaigning into Thursdays through Mondays, as he spends the rest of the week in Washington for his senatorial duties.

He might just be the most polarizing Louisiana politician in office.

On one side, he has staunch defenders — those who laud him as a tireless advocate for his causes and as a staunch conservative and opponent of cronyism.

His critics, meanwhile, claim he’s calculating and unwilling to work with those who disagree with him. And that’s when they aren’t outright mocking him for a sex scandal he’d clearly prefer to leave in the past.

Vitter, 54, is indisputably the most well-known candidate running for governor this year and has been a clear front-runner in the race since formally launching his campaign more than a year ago.

Gov. Bobby Jindal, who is running for president, is term-limited and can’t seek re-election. That’s left a wide-open fight for the state’s top office, with Republicans Vitter, Scott Angelle and Jay Dardenne and Democrat John Bel Edwards emerging as the four main contenders.

Vitter’s campaign closely resembles that of an incumbent.

As the parade rolled around the block at this year’s Shrimp and Petroleum Festival in Morgan City, Vitter confidently stood perched atop an antique firetruck, waving to the crowd several feet below him. Young supporters wearing T-shirts emblazoned with his campaign logo were the ones throwing cups and candy to revelers from the lower back area of the truck.

Vitter has held closed-door meetings with top-level officials and constituents in recent months, skipped several gubernatorial forums and will likely pass on some of the upcoming televised debates.

He’s conducted few off-the-cuff interviews and hasn’t courted the sort of media attention that his opponents have sought.

He’s also the best financed candidate and continues to significantly out-raise his opponents. In the most recent campaign finance reports, which were due in July, Vitter had raised $1.3 million to Angelle’s $413,000, Dardenne’s $408,000 and Edwards’ $246,000.

“I think it’s going great,” Vitter told The Advocate recently. “I feel really energized as I go around the state.”

Vitter and his wife, Wendy, a former prosecutor, live in Metairie and have four children: Sophie, Lise, Airey and Jack.

A New Orleans-born Roman Catholic, Vitter has degrees from Harvard and Oxford University, where he was a Rhodes Scholar. He then earned a law degree from Tulane in New Orleans and worked as an attorney before entering politics. Those who know him well admit he can sometimes come across as chilly but attribute it to his low tolerance for disappointment and inability to suffer fools.

“He expects those around him to be prepared. He’s very demanding,” said U.S. Rep. Charles Boustany, of Lafayette, who has endorsed Vitter in the race and known him since the 1990s. “When he makes his mind up, he can be stubborn, but I think that’s what we need.”

State Treasurer John Kennedy also has endorsed Vitter in the governor’s race. Kennedy remembers meeting him when Vitter first contemplated running for office.

“I’ve known David a long time,” Kennedy said.

Vitter was first elected to the Louisiana Legislature representing suburban New Orleans in 1992. Kennedy worked in the Governor’s Office, under Govs. Buddy Roemer and Mike Foster, at the time. Kennedy says he and Vitter were like “kindred spirits.”

“Neither one of us were members of ‘the club,’ ” Kennedy said, alluding to insiders who engaged in back-room deals with special interests. “Members of that club have at times called us ‘crazy’ or a ‘rebel.’ ”

Kennedy said he thinks that “rebel” spirit will make Vitter a good governor.

“I think at this juncture in Louisiana history, we need a governor who is a cross between Socrates and Dirty Harry,” he said.

And Vitter, Kennedy said, falls into that area between philosopher and ruthless cop.

“He doesn’t much care about the approval of his political peers,” Kennedy said.

One of Vitter’s most lasting accomplishments as a state lawmaker is probably his successful push for term limits. He also sought out reforms to the coveted Tulane scholarships that lawmakers doled out to their cronies.

Vitter was elected to Congress in 1999, after U.S. Rep. Bob Livingston resigned when it was revealed Livingston had cheated on his wife.

Vitter followed that with a successful run for the U.S. Senate in 2004.

The next chapter in his life story is well-known at this point: Just three years later, Vitter faced a sex scandal of his own when his number was connected to a Washington prostitution ring. Despite political pressure, Vitter stayed in office and was re-elected in 2010 after having admitted to a “serious sin” that he has since refused to openly discuss.

As the governor campaign has ramped up, it’s clear that a target has been firmly planted on Vitter’s back.

“I fully expected that,” he said. “It comes with being a strong front-runner from the start.”

His opponents have not shied away from openly drawing attention to his prostitution scandal, despite his 2010 victory.

Vitter’s supporters say the scandal hasn’t made them think twice about throwing their support behind him.

Tu Thomas Hoang, a 28-year-old attorney from Marrero, was among the volunteers in Vitter shirts following him through the crowd at the Vietnamese festival. He said he likes Vitter’s social conservatism, as well as his small-government, less-regulation positions.

“He’s a very hard-working man,” Hoang said. “We see that in this community.”

Hoang said Vitter has consistently pushed legislation important to South Louisiana’s Vietnamese population.

“He is one of our main supporters in Congress,” he said.

Despite other Republicans in the race holding similar positions, Hoang said he wasn’t familiar with them.

“We have a track record with Senator Vitter,” he said. “He hasn’t failed us yet.”

Many describe that sort of “What have you done for me lately?” aspect as being key to Vitter’s appeal. And after having served in elected office since being a state lawmaker in the 1990s, he’s had the ability to help a lot of people. Time and again, his supporters recount instances of seeking assistance from Vitter’s office and receiving it.

One of his campaign ads this year — actually a throwback to a 2010 ad — features a woman who credits Vitter with helping her secure a liver transplant after she contracted hepatitis C. The woman, Deborah Cazalot, told The Advocate that she received no help from other elected officials she reached out to, but Vitter’s office promptly followed up and helped her get a Social Security disability hearing that ultimately helped her get on the transplant list.

“We have a great army of volunteers in every part of the state,” Vitter said.

Hoang, who described himself as a religious social conservative, said he knows Vitter’s sex scandal remains a stain on his candidacy but doesn’t see it as an issue that should preoccupy the minds of the public or sway many votes in the campaign.

“His wife has forgiven him; she didn’t divorce him,” he said. “The Christian faith is all about forgiveness, and if she can give him that, so can I.”

“My main concern is corruption in government,” Hoang added.

Vitter still has plenty of detractors — that’s for certain.

Recently, ads have started running on television across the state reminding voters about the prostitution scandal, as well as Vitter’s changing position on Common Core. Vitter previously favored the education standards but has since taken up the more conservative view and turned against them.

His opponents regularly have started questioning his absence from forums, his refusal to discuss his “serious sin” and whether he broke the law, and his effectiveness as a leader.

In Washington, he has developed a reputation of sorts for being stubborn and largely unavailable to the media, but also for being unafraid of going to bat for his causes. In a Politico article earlier this year, several of his GOP colleagues — named and unnamed — depicted him as difficult and accused him of latching onto causes simply to build up his own political ambitions.

U.S. Sen. Bill Cassidy, who got help from Vitter in defeating incumbent Mary Landrieu last fall, said he chalks up those complaints to “prejudice.”

He recalled how Vitter worked across the aisle with Democratic U.S. Sen. Barbara Boxer, of California, on the Water Resources Reform Act.

The House was at an impasse on several provisions that Louisiana wanted, so the state’s delegation relied heavily on Vitter working out a compromise with Boxer that would include those provisions in the final version, including additional money from the Harbor Maintenance Trust fund and hurricane protections.

“That was a remarkable achievement,” Cassidy said.

Vitter’s most recent high-profile charge has been his effort to eliminate health care subsidies from the federal Affordable Care Act for lawmakers and their staffers. That throwback to his tackling issues directly affecting his colleagues has drawn ire from some in Washington, but praise from others who say he doesn’t bow to the establishment.

“David is effective, he’s pragmatic and he’s willing to change things,” Cassidy said. “Right now, Louisiana has some big issues, and we have to be willing to change old patterns of activity.”

Follow Elizabeth Crisp on Twitter, @elizabethcrisp. For more coverage of Louisiana state government and politics, follow our Politics blog at http://blogs.theadvocate.com/politicsblog.