Unable to shake his Republican rivals in the governor’s race, U.S. Sen. David Vitter launched television attack ads over the weekend against Lt. Gov. Jay Dardenne and Public Service Commissioner Scott Angelle.

The ad against Dardenne calls him a “liberal,” which is an epithet in a state where not a single Democrat holds statewide office. The accusation would probably come as a surprise to those who have voted for Dardenne over the years. He has won eight straight elections as a Republican since 1988.

The Vitter campaign commercial against Angelle says he has a lot in common with President Barack Obama. It says he was a Democrat for 31 years — Angelle switched to the Republican Party in 2010 — and features several photos of Obama and Angelle simultaneously. The spot also says Angelle took positions on the Public Service Commission that were favored by the Obama administration.

Vitter’s super PAC, Fund for Louisiana’s Future, also launched an attack ad against Angelle that suggests he did nothing to prevent the Bayou Corne sinkhole.

The ads by Vitter and his super PAC indicate that he and his strategists believe only one Republican will finish first or second in the Oct. 24 primary and thus make the Nov. 21 runoff.

“Those are the guys he needs to defeat to face John Bel Edwards in the runoff,” said Ed Chervenak, a University of New Orleans political scientist. Edwards, from Amite, is the lone Democrat among the four major candidates.

The ads might come as a surprise to people who have heard Vitter say repeatedly on the campaign trail that the election’s focus should be on the future. All three ads focus on past actions of his two Republican opponents.

“He may want to make his campaign about the future, but he isn’t holding to his own words with these ads,” said Joshua Stockley, a political science professor at the University of Louisiana at Monroe.

The attack ads by Vitter and his super PAC — which under election law are not supposed to coordinate their activities — don’t come as a surprise to the Dardenne and Angelle campaigns. Both the Vitter campaign and his super PAC have been sitting on millions of dollars raised from oil, gas, chemical and other business interests that have major issues before the next governor and state Legislature. Angelle and Dardenne also have raised big dollars from business interests, although much less.

Accompanied by foreboding music, the anti-Dardenne spot calls him “dangerous” and says that he voted against a pro-life position six times as a state senator, for taxes 21 times and in 2006 to prevent people living in the country illegally from taking away jobs from Louisiana workers. In that 2006 vote, Dardenne initially voted against the measure but, after it was amended, supported the final version that became law.

The Dardenne campaign cried foul on Sunday.

“These are the same false attacks that opponents have used against me for a decade, and the voters of Louisiana have elected me statewide four times,” Dardenne said in a statement. “I am pro-life and my record clearly shows that, as does the 100 percent record from Louisiana Right to Life. This is typical Washington politics, playing fast and loose with the facts. David Vitter says I’m dangerous, and he’s right. I’m dangerous because I’m the man who will beat him in a runoff and keep him in Washington.”

Louisiana Right to Life’s website says Dardenne had a 62 percent record during his tenure in the state Senate and scored 100 percent on a questionnaire as lieutenant governor. Vitter has scored a 100 percent rating, as did Edwards. Vitter and Angelle scored 100 percent in their answers to Louisiana Right to Life’s candidate questionnaire. Dardenne and Edwards haven’t answered it, the group says.

Vitter’s ad linking Angelle to Obama is a go-to strategy that he used effectively in his 2010 re-election campaign against Charlie Melancon, a Democratic congressman, and that his campaign strategists used last year to elect then-Rep. Bill Cassidy to the U.S. Senate by defeating Mary Landrieu, the Democratic incumbent. In May, Obama had a 94 percent negative rating among Republicans in a Southern Media and Opinion Research poll.

“To those who know David Vitter, these attacks come as no surprise,” Ryan Cross, Angelle’s campaign manager, said in a statement. “He is just another Washington politician that can’t run on his own record, so he’s trying to distort and smear Scott’s through false attacks. Scott is a proven conservative leader with momentum and a message that has clearly resonated with the hard-working people of Louisiana. David Vitter’s poll numbers are collapsing so, in turn, he’s decided to bring trashy Washington-style smear politics to Louisiana.”

Both the Dardenne and Angelle campaigns promised to detail their objections to the Vitter ads on Monday when the two men will be joined by Edwards at a debate organized by the Press Club of Baton Rouge. Vitter will miss the event to travel to Washington, D.C., his campaign has said.

The Vitter super PAC ad against Angelle on Bayou Corne concerns his role as Gov. Bobby Jindal’s secretary of the Department of Natural Resources. Reporting by The Advocate shows Angelle told residents on Aug. 4, 2012 — the day after a sinkhole that eventually gobbled up their homes appeared — that the well drilled by Texas Brine Co. LLC had problems in 2010.

Residents and parish officials at the time criticized Angelle for failing to tell them that his agency had known that tests showed the well might have breached the salt cavern walls.

Angelle resigned on Aug. 8, 2012, to run for the Public Service Commission seat, a decision that had been in the works for months. The anti-Angelle ad makes it seem, however, as if he resigned from his post at DNR to avoid responsibility for the issue.

Either way, Angelle clearly left behind some bruised feelings.

“He was the captain of the ship, and when the ship started sinking, he abandoned the ship,” said Mike Schaff, a 65-year-old former Bayou Corne resident who describes himself as a tea party Republican, but not one who will support Vitter. “I wanted him (Angelle) to take charge, even if he was planning on resigning, but to stay on until the situation was in hand.”

Mark Ballard, of The Advocate Capitol news bureau, contributed to this report. Follow Tyler Bridges on Twitter, @TegBridges. For more coverage of the State Capitol, follow Louisiana Politics at http://blogs.theadvocate.com/politicsblog.