Nearly two years before we learn the results of the 2010 governor's race, the identity of the likely winner is clear: Northern California.

More than half of California's population may live south of the Tehachapi Mountains, but the state -- in matters of politics, governance and civic engagement -- is tilting decidedly north. Just look at the race to succeed Gov. Arnold Schwarzenegger.

The Republican contest is shaping up as a Silicon Valley primary, with three candidates hailing from within a half-an-hour drive of the Googleplex. Two -- Insurance Commissioner Steve Poizner and former EBay Chief Executive Meg Whitman -- are high-tech billionaires, a species the north produces far more of than the south. The third is a former congressman and Schwarzenegger budget director, Tom Campbell, whose House district included Stanford University and much of Silicon Valley.

"It's the revenge of the 650 area code," joked Dan Schnur, a former Republican political consultant and self-described Northern California refugee who now directs the Jesse Unruh Institute of Politics at USC.

The Democratic side has a touch more geographic diversity. The likely candidates are Mayor Gavin Newsom of San Francisco; Lt. Gov. John Garamendi, who lives near Sacramento; and, of course, Jerry Brown, attorney general/former governor/former Oakland mayor, who hails from -- take your pick -- the East Bay, outer space or the 1970s. And in the wings? Dianne Feinstein, former San Francisco mayor and current U.S. senator.

Of course, Southern California does have one probable candidate with a chance at winning the race, but only one. And if history is any guide, Antonio Villaraigosa won't be the next California governor. That means the part of the state that by the numbers should wield the most power at the ballot box -- and lead state government -- will not.

Many Californians haven't lived here long enough to know this, but a Northern California governor would represent real change. The state has had uninterrupted rule by the south -- by Brentwood's Arnold Schwarzenegger, West Hollywood's Gray Davis, San Diego's Pete Wilson and Long Beach's George Deukmejian -- since 1982, when the office was held by, well, Jerry Brown. And Brown was a part-time Southern Californian when he won the governorship in 1974. (He grew up in San Francisco and moved to L.A. in the late 1960s to run for a seat on the community college board.) When you recall that Brown's predecessor was Ronald Reagan, it's been more than 40 years since a pure Northern Californian -- Jerry's father, Pat Brown, a San Francisco native -- governed our state.

So why won't Villaraigosa be joining that list? And why aren't there others from south of the Tehachapis?

For starters, it's telling that all of those successful gubernatorial candidates from Southern California built identities separate from the politics of the region. Actors Schwarzenegger and Reagan had national and even global fame because of their movie work. Davis and Deukmejian built reputations primarily in Sacramento through decades of legislative and other government service. Statewide political careers of that length are harder to build now because of term limits.

The truth is, Southern California's local politics don't provide a solid political base for the next level of governance. The region isn't cohesive: L.A.'s politics aren't San Diego's or Riverside's. And even though Los Angeles dominates, its size is an obstacle for politicians seeking to build the name recognition and coalitions required to support a run for high office. In an age of media fragmentation, this challenge is even greater. "Because the L.A. media market is so big, it is hard for someone to emerge who is strong and well known," says political consultant Kam Kuwata.

Adding to the relative difficulty of building a political career here is the fact that Southern California voters are significantly less politically engaged than their counterparts in Northern California. In last June's state primary elections -- primaries are the first crucial gubernatorial hurdle -- just 14% of the Los Angeles County adults who were eligible to vote cast ballots. The figure was 29% in San Francisco and above 20% in each urban Northern California county. The same divide is clear even in high-turnout elections like last November's presidential contest. In that election, 58% of eligible Los Angeles County citizens cast votes. The figure was 65% in San Francisco and above 60% in all Bay Area counties.

In most places, great politicians are forged in competitive elections, and our region has fewer and fewer such contests. The March 2007 city elections in L.A. saw a turnout of just 10% of registered voters. Turnout was in the single digits for that year's school board races. In next month's city elections, we may see a similarly low turnout because the mayoral election is barely being contested.

Which brings us back to Villaraigosa. Southern California's most direct path to political prominence is to be elected mayor of Los Angeles. Villaraigosa's success in winning the office means he has mastered the divisions of the city, but historically, that hasn't been enough. No elected mayor of Los Angeles has ever been elected governor of California. (William Stephens, who was appointed mayor in L.A. for two weeks in 1909, became governor in 1917 when the incumbent resigned and won a full term in 1918).

Two of the last three mayors, Tom Bradley and Richard Riordan, tried to make the leap to the Capitol, and each was felled -- in no small part because of their strong association with L.A.

Aides to Deukmejian, who ran against Bradley in 1982 and 1986, told me that during those gubernatorial campaigns, they made a point of linking Bradley to L.A. as often as possible. The Los Angeles brand, for all its global allure, is a state political albatross. A lot of Californians associate the city with sprawl, traffic snarls, crime and a needy, failing school system. The argument that a candidate could do for the state what he'd done for L.A. is not an attractive one.

All this supports the notion that it will be the north, not the south, that takes over in Sacramento. Villaraigosa has tried to seem bigger than L.A. -- muscling his way into national debates on education, immigration and stimulus allocations -- but polls show he's hardly a statewide household name. Now his aides are spinning out a demographic argument for his gubernatorial candidacy: The state's increased number of Latino and labor-friendly voters, both key Villaraigosa constituents, give him an edge. But hatred of Los Angeles and Villaraigosa's own personal and political weaknesses -- including an extramarital affair and his losses in the battle to take over the schools -- make him a long shot.

What of other potential Southern California challengers? It's possible another outside-of-politics, movie-star type could emerge and try to carry on the tradition. But given Schwarzenegger's problems, the moment for that genre of candidate probably isn't right. It's also possible a city other than Los Angeles might have the grass-roots civic wherewithal to generate a contender, but there's no sign of it yet.

Of course, given the state's recent record of governance, perhaps it's not entirely a bad thing that the next governor won't be from Southern California. Perhaps the only wound from such an outcome would be to local political prestige. Or maybe, given the state of our civic culture, no one would even notice, or much care.