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Editor's note: Errol Louis is the host of "Inside City Hall," a nightly political show on NY1, a New York City all-news channel.

(CNN) -- Barely a month after pulling off a smashing re-election victory, Republican New Jersey Gov. Chris Christie finds himself fending off a local scandal that has become an early stumbling block on his road to a run for president in 2016. And despite Christie's cries of foul -- he claims Democrats are making a mountain out of a molehill -- all indications are that the Republican hopeful has nobody to blame but himself for his current woes.

As he prepares to ascend to the national stage -- and the glare of the spotlight that comes with it -- Christie must change some of the funky, in-your-face combative style that serves him well in New Jersey but is likely to cause voters in places such as Iowa and New Hampshire to recoil in horror.

Democrats in the New Jersey Legislature are still using hearings and subpoenas to piece together the particulars, but the general shape of the controversy is already known.

In early September, some serious mischief appears to have been done by close associates of Christie's who work at the Port Authority, a gargantuan $2.57 billion agency that controls the bridges and tunnels between New York and New Jersey along with area airports and the World Trade Center.

Without notice to the public or the agency's executive director, the Port Authority abruptly closed a set of local roads leading to the George Washington Bridge -- the busiest crossing in the world, handling 100 million vehicles a year -- causing massive traffic snarls in Fort Lee, New Jersey. Democrats believe the shutdown was an act of political retaliation because the town's mayor, Mark Sokolich, refused to endorse Christie's re-election.

Nobody is admitting guilt, and Christie calls the political-payback accusation "crazy." But two political appointees at the agency who are close to Christie -- one is a childhood friend -- have resigned. "Mistakes were made," the governor acknowledged in an hourlong press conference.

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As local Democrats demand e-mails, memos and sworn testimony, the national party swiftly pounced, releasing a two-minute video called "Chris Christie's Bridge Scandal Explained."

The controversy will likely be long forgotten by the time the race for president gets under way in earnest, but it's safe to assume that no politician likes to see stories with headlines that include words such as "scandal" and "payback."

The idea that Christie might have inflicted pain on an entire town to settle a political score with its mayor also plays into an unflattering image of Christie as a bully -- a reputation underscored by videos that show the governor berating teachers, journalists and town hall participants.

Christie fans in New Jersey love to see him telling people off, but that appeal doesn't necessarily translate to the national stage. In fact, it's safe to assume that if Christie runs for president, those videos will resurface as attack ads that question his judgment and self-control.

More importantly, the controversy takes some of the luster off Christie's case -- spotlighted in a recent Time magazine cover story -- that he, rather than fire-breathing tea party conservatives, can best lead the Republican Party to victory in 2016.

A big part of Christie's appeal -- an image he has carefully cultivated -- is that he's a Republican with proven ability to win over Democratic and independent voters.

A former prosecutor, Christie has built a case for his crossover appeal by pointing to his two victories in New Jersey, a state where Democrats outnumber Republicans by 700,000 and independent voters outnumber both parties.

"Maybe the folks in Washington, D.C., should tune in their TVs right now, see how it's done," Christie crowed on Election Night this year, challenging congressional Republicans -- and the national Republican Party -- to follow his lead.

Christie's much-publicized working relationship with President Barack Obama, which infuriated some Republicans, was another step in the same direction, as was his rounding up support from Democratic Party officials -- an effort so successful that Christie's Democratic opponent, state Sen. Barbara Buono, publicly declared that "Democratic political bosses — some elected and some not — made a deal with this governor despite him representing everything they're supposed to be against," which she called a "betrayal."

It could turn out that Christie's followers went overboard in the effort to round up Democratic support -- and that their zeal led to the punishment allegedly visited on Democrats such as the mayor of Fort Lee. That could turn Christie into a punching bag for national Democrats and erode his crossover appeal.

For the sake of his presidential ambitions, it's in Christie's best interests to get all the facts about the bridge controversy on the table as quickly as possible -- and then begin a long-term makeover to ensure that his image remains one of a blunt, tough-talking guy -- not a petty and short-tempered bully.

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The opinions expressed in this commentary are solely those of Errol Louis.