If it’s possible to shake up a race a year ahead of time, Public Service Commissioner Scott Angelle did that last week when he announced he’ll run for governor in 2015.

Other than a possible entry by New Orleans Mayor Mitch Landrieu, whose been known to jump into big campaigns relatively late in the game, Angelle’s candidacy has the most potential to alter what had become a pretty stable storyline.

Until now, the contest has boiled down to two big questions.

First, would John Bel Edwards, a state lawmaker who’s not nearly as well-known as either fellow Democrat Landrieu or the race’s two big Republicans, emerge as enough of a force to rally the party faithful? Or would Democratic voters flock to the perceived GOP moderate in the field, a spot that Lt. Jay Dardenne had to himself until now, in the hope of warding off a victory by the more ideologically inclined U.S. Sen. David Vitter?

And second, would Vitter succeed in shifting his politics, shaped most recently by the Washington partisan wars in which he’s been an enthusiastic combatant, far enough toward the middle to squeeze Dardenne out of a runoff?

Angelle upends all that. As a fourth major candidate, his entry creates an air of unpredictability that’s common to open primaries featuring large fields. As a native of Breaux Bridge, he adds a new regional dynamic to the contest (Vitter’s from Metairie, Dardenne from Baton Rouge and Edwards from Amite). As a former top aide to Gov. Bobby Jindal, his presence makes the current governor’s record an issue. And as a relatively recent Democrat, he complicates the role of party politics even more.

The first thing handicappers should know, though, is that Angelle is undeniably charismatic. As Roy Fletcher, a consultant for Angelle’s PSC race who’s in negotiations to handle the gubernatorial campaign, put it, “he’s got the verbal skills of (Buddy) Roemer and (Edwin) Edwards put together.”

Asked what else Angelle brings to the race, Fletcher pointed to deep roots in Cajun country, long a swing area in statewide elections. “It’s cultural,” he said. In the past, winning Cajun politicians have been conservative Democrats such as Kathleen Blanco, Angelle’s onetime boss, and former U.S. Sen. John Breaux. But Angelle’s own conversion mirrors a change many voters in the area also have made.

Fletcher also cited Angelle’s experience at both the local and state levels. He served on the St. Martin Parish police jury and as parish president. Blanco hired him as secretary of natural resources, which gave him oversight of the oil and gas industry. Gov. Bobby Jindal kept him on and later appointed him interim lieutenant governor after Landrieu left the job and before Dardenne was elected to replace him. He switched parties in 2010, and won the PSC seat in 2012.

His presence raises a long list of questions, too.

Will critics succeed in tagging him as a Jindal guy, at a time when the governor’s approval rating has dropped to 34 percent, according to a recent poll by the Democratic firm Public Policy Polling, and the other main Republicans are running as agents of change? (For a hint of how Angelle will answer that, Fletcher invoked yet another former governor: Mike Foster, a pragmatist who wanted to “get things done.”)

And where does he stand on other issues, anyway?

We know he’s pro-oil and gas; when he switched parties, he said that his main motivation was his disagreement with Obama administration’s policies on the subject, particularly after the BP spill. But what about higher ed, health care, taxing and spending, and social issues?

And both Vitter and Dardenne have pointedly denounced Jindal’s opposition to the Common Core education standards and broadly hinted that they’d accept the Affordable Care Act’s Medicaid expansion, another area where Jindal has dug in his heels. Will Angelle do the same?

How Angelle navigates these minefields will tell us a lot about what sort of campaign he’ll run. Not to mention how well he’ll fare.

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