“HI THERE,” a pair of flirtatious grannies coo at the governor of New Jersey, Chris Christie, with much waving of red-taloned hands. “You’re skinny,” they cry, referring to the pounds he has lost since having gastric-band surgery earlier this year. (He now looks more like a panda than a grizzly.) The grannies cackle at their daring, and are rewarded with a blown kiss.

Mr Christie was on the campaign trail on June 10th, squeezed onto a tiny stage in a rain-lashed tent on a closed-off street in Union City, a scruffy suburb across the Hudson river from Manhattan, a world away. Up for re-election in November, the Republican governor was in Union City to be endorsed by the mayor, a Democrat, as a salsa band shivered and pensioners eyed a free Cuban buffet cooling on a side table.

If a second term as governor were his only goal, Mr Christie would not need to try so hard. He could win the race in a stroll—polls put him way ahead—without a single vote from Union City, a Democratic stronghold. But he has national ambitions, so he wants to win by the biggest margin possible. A Republican in a state won easily by Barack Obama, he is working to scoop up Democratic endorsements, which are vital for impressing swing voters watching the evening news.

He is also keen to reduce the number of diehard Democrats who vote in November. Hence his crafty response to the recent death of Frank Lautenberg, one of New Jersey’s two Democratic senators. He used his powers as governor to appoint a Republican replacement (national Republicans would not have forgiven him anything else). But in a gift to Democrats, the new senator will serve only a few months, rather than the rest of Mr Lautenberg’s term. And Mr Christie arranged for a fresh Senate election to be held expensively in October, so as not to coincide with his own race. That way, he avoids facing the extra Democrats who will turn out to vote for Cory Booker, the celebrity mayor of Newark, who is expected to win the Senate seat. It is vintage Christie: a dash of bipartisanship on a dollop of self-interest.

Mr Christie is big box office. Within New Jersey, he is the tax-cutter who said public-sector pay and perks should shrink—and meant it. He has picked verbal brawls with teachers’ unions and anyone else who gets in his way. Nationally, he is popular, with high net approval ratings from Republicans and Democrats, though a hefty minority of Republicans loathe him. Audiences know him as a finger-jabbing, cut-the-crap Republican who defied his party to take Mr Obama round towns wrecked by Hurricane Sandy, days before the 2012 election (handing a propaganda gift to the president, conservatives growled). He cracks weight gags with late-night TV hosts. He is a Bruce Springsteen fanatic who longed for The Boss to like him back (and wept after the leftish singer hugged him at a Sandy benefit concert).

Nobody doubts that he covets the Republican presidential nomination in 2016. And because to his party’s Taliban wing he is an apostate—eg, he supports some gun controls, backs immigration reform, nominated a gay man to the state Supreme Court and has signed New Jersey up to Obamacare’s expansion of health coverage for the poor—he has only one path through the primary process. That is to be the Republican who won re-election in a Democratic state by 20 points or more. Then he can ask his party if they prefer purity or winning.

Obstacles loom. Quite a lot of Republicans, especially the sort who vote in primaries, think that conservative purity could be a fine route to victory, if their party ever had the gumption to try it. More worryingly for Mr Christie, not everyone in America adores New Jersey, from its manners to its endemic corruption. The fact that as a federal prosecutor Mr Christie indicted more than a hundred public officials is impressive, but it reminds folks that he looks like a character from “The Sopranos”.

Mr Christie is one of several north-easterners who dream of becoming president. Take the Amtrak train from Washington, DC to Boston, and at half a dozen stops a local champion is being talked of as a contender, from Vice-President Joe Biden in Delaware to the Democratic governors of Maryland, New York and Massachusetts (Hillary Clinton, with homes in Washington and upstate New York, makes six, though she is more inter-galactic than local nowadays).

The north-east, graveyard of White House bids

Yet the road from the north-east to the White House is narrow and steep. Remember Mitt Romney? Or John Kerry? Or Michael Dukakis? North-easterners are not like other Americans. They go to church less, own fewer guns and drink more wine. Six of the eight Amtrak corridor states have abolished the death penalty and six allow gay marriage. North-eastern cities and suburbs harbour an endangered species: fiscally conservative, socially liberal Republicans. The Christie pitch is that he can win over north-eastern moderates, but is not one of them. He sells himself not as a centrist but as a problem-solving conservative, impatient with party labels. That is too glib: there are points of real difference in politics, as he knows. Over the years, he has hardened his stance on such issues as abortion and blurred it on others, such as climate change, in line with Republican taboos.

Mr Christie’s advisers say he will win New Jersey with a coalition of Republicans, independents, fiscally conservative Democrats and skilled workers. Though they will not talk of the White House, that certainly sounds like a national battle-plan.

In essence, New Jersey’s rumpled, charming, bullying governor embodies a bet: that the Republicans must develop a bipartisan appeal, or perish. Perhaps he will fall flat once he leaves his beloved New Jersey. But he is becoming the most interesting Republican of the 2016 pack.

Economist.com/blogs/Lexington