An important seat was up for grabs in Washington, D.C., and back in Louisiana, senior Republicans didn’t want to take any chances. So rather than risk an open-primary free-for all, they set out to winnow the field, identify a consensus candidate and present voters with a united front.

The year was 1999. The office was the 1st District congressional seat suddenly vacated by incoming House Speaker Bob Livingston, who walked away on the day of the Clinton impeachment after Hustler magazine publisher Larry Flynt unearthed evidence that he had strayed from his marriage.

The elder statesmen, concerned that a profusion of Republican candidates could split the vote and create an opening for a Democrat or former Klansman David Duke, rallied behind former Gov. Dave Treen — a beloved figure in the party and, at 70, someone who would just hold the seat for a few years while others sorted out an orderly succession plan. Hopeful after hopeful, including then-state Rep. and current 1st District U.S. Rep. Steve Scalise, fell in line.

The guy who didn’t play along? A fiercely ambitious state representative named David Vitter, who resigned his legislative seat, wrote checks for more than $700,000, ran a populist campaign against the powers-that-be and their backroom deals, and sent Treen back into retirement.

The performance was vintage Vitter, who by then had long since established himself as a thorn in his fellow pols’ sides.

It was Vitter who brought term limits to the Capitol, to the distinct irritation of the careerists. It was Vitter who pushed to disclose which politicians had claimed free educations for their friends’ and contributors’ kids, their relatives and in some cases even their own children, using the previously under-the-radar Tulane legislative scholarships. And when reporters were looking for someone to quote, well, Vitter was often first in line.

Actually, make that vintage 1990s Vitter.

These days, the onetime outsider could pass for the ultimate party boss. In head-turning contrast to his early, in-your-face period, the second-term U.S. senator is now the one convening those closed-door meetings — including the ones in which he reportedly pressured other candidates to step aside and give U.S. Rep. Bill Cassidy a clear shot at his vulnerable Democratic colleague Mary Landrieu (tea-party newcomer Rob Maness, doing his best impersonation of early Vitter, refused to stand down and wound up forcing a runoff).

Vitter did more than that on Cassidy’s behalf. He also provided a top aide to run the campaign, as well as the winning blueprint he had used in his own 2010 race, when his prostitution scandal threatened his political survival: Don’t make the election about you, make it about President Barack Obama. It obviously worked like a charm, twice.

By the time the Cassidy race came along, Vitter had already done plenty to turn the GOP into Louisiana’s dominant party. With the help of his own long-ago term-limits bill, a delayed-reaction measure that kicked in just in time for the 2007 election, Vitter led recruitment of a new generation of conservative legislative candidates. He also got on the phone and convinced many long-term Democrats in conservative districts to switch, a suggestion that carried an implied threat of a Republican opponent if they didn’t.

Louisiana was turning red on its own, but Vitter, perhaps more than anyone, helped seal the deal. Now that Landrieu’s on her way out, every statewide office and both branches of the Legislature are in Republican hands.

And there’s more. If Vitter wins his upcoming bid for governor, he would have the chance to appoint his own successor (one of the candidates he talked out of a race this year, U.S. Rep. John Fleming, is already out there raising his hand). That means that a Gov. Vitter could be responsible for installing not one but two senators.

So has Vitter changed? Well, yes and no. He’s clearly learned to work better with others over the years. But both his early and more recent triumphs reflect the same keen strategic sense and killer instinct he’s always had.

Sure, he’s facing a pair of seasoned GOP rivals next year, Lt. Gov. Jay Dardenne and Public Service Commissioner Scott Angelle, and perhaps others. And yes, he took a rare stumble when he revoked his earlier endorsement of the Common Core education standards — a move that was clearly designed to distinguish him from unpopular Gov. Bobby Jindal — and joined Jindal as a converted critic. Everybody makes mistakes now and then.

This much has been a constant for more than two decades, though. When it comes to figuring out how to win elections, Vitter makes fewer than most.

Stephanie Grace can be contacted at sgrace@theadvocate.com. Read her blog at http://blogs.theadvocate.com/gracenotes. Follow her on Twitter, @stephgracenola.