A race to the center : The three Republican candidates hoping to succeed Arnold all seem a lot like ... Arnold.

Almost three years ago, in the glow of a decisive reelection victory, Arnold Schwarzenegger proclaimed himself a “post-partisan” leader who would not be limited by the dogma of the two major parties. Ever since, conservative Republicans in California have quietly smoldered, avoiding open revolt against their party’s nominal leader but counting the days until one of their own could replace Schwarzenegger in the governor’s office.

But as the field of candidates for the 2010 election begins to take shape, it is increasingly likely that the eventual Republican nominee will strongly resemble the current governor in almost everything other than the depth of his accent and the size of his biceps.

On the issues, all three current GOP candidates -- former congressman Tom Campbell, state Insurance Commissioner Steve Poizner and former EBay Chief Executive Meg Whitman -- represent about the same ideological turf that Schwarzenegger has occupied since entering public life. They combine a fundamentally conservative approach to economic and public-safety issues with a more moderate grounding on social and cultural matters.

The absence of a traditional social-conservative candidate in the mix is not caused by a lack of such active Republicans -- politicians and voters -- in the state. But the money is with the centrists -- and likely to remain so.

All three Republican contenders are emphasizing their economic agendas to the primary audience, positioning themselves well to the right of the way Schwarzenegger has governed (but not that far from the way he campaigned). As the primary draws closer, look for their criticisms of his record on taxes and spending to become much less polite.

Schwarzenegger’s brand of environmental advocacy appears to be an early casualty in the GOP race as well. The candidates are pulling back from his strong stance on emissions control, which they argue could be costly to the economy in a time of deep recession. They will also run hard on issues relating to crime (longer sentences and additional prison construction) and illegal immigration (border control).

All three candidates are in favor of abortion rights and stem cell research, however, and the absence of a pro-life challenger may make it easier for them to soft-pedal these important social issues -- which may keep the party’s internal divisions on them from taking center stage.

On another social issue, same-sex marriage, the candidates have a mixed response (Whitman and Poizner were pro-Proposition 8; Campbell opposed it). However, unlike abortion and stem cell research, where California voters lean heavily toward the pro-choice position, public opinion on same-sex marriage is much more closely divided. However they fall on the issue in the primary, it’s less likely to help or hinder them in the general election.

But the other key factor here is the financial reality of running for governor in the 21st century. Both Whitman and Poizner have sufficient personal wealth to allow them to spend tens of millions of dollars of their own money on the race. The party’s largest donors tend to be much more centrist than its grass roots, and they would pay little attention to a contender representing the GOP’s right flank. So the most prominent conservative elected officials -- in Congress, in the Legislature and even local officeholders -- are unlikely to enter a field in which they almost certainly will be dramatically outspent. Better to run for a down-ticket statewide office or to wait for a future election, one with fewer multimillionaires with whom to contend.

At this early stage of the race, Atty. Gen. Jerry Brown -- who isn’t yet a formal candidate -- has high approval ratings and name recognition, and with San Francisco Mayor Gavin Newsom’s decision to leave the race, the possibility of an uncontested path to the Democratic nomination. While the Republican contestants throw javelins at each other over the next several months, he could marshal resources and position himself toward the center.

Combined with Schwarzenegger’s low poll numbers, these are ingredients that make the Democrat an early front-runner. But the Republican centrists may be able to lessen those advantages.

For almost a quarter of a century, the ideological mix that Campbell, Poizner and Whitman all represent has been a virtual prerequisite for top-of-the-ticket Republican success. Since George Deukmejian was reelected governor in 1986, the only Republicans to win campaigns for governor or U.S. senator have been Schwarzenegger and fellow abortion-rights advocate Pete Wilson. Poizner and Whitman’s money might not guarantee either of them success in the primary or the general election, but it may force the formulation of a field of GOP centrist candidates. While history suggests that may be better for the party’s chances in November, the challenge of persuading a conservative Republican base to turn out for a centrist nominee remains.

In the end, that may be the defining question in the election of California’s next governor.