WORD HAS IT that a leading California Republican has devised the perfect slogan for GOP frontrunner Richard Riordan's gubernatorial campaign: "More Conservative Than Bloomberg." To many California conservatives, that may be optimistic. Badly in need of a win next year after three straight losing election cycles, California Republicans haven't set the bar very high for Riordan. "He doesn't have to convince them that he's a conservative Republican, but only that he's a Republican," says one party insider. If Riordan can do that, he adds, "a lot of that complaining will go away." That also may be optimistic. The California Political Review's recent cover story on Riordan warns against "Republican Self-Mutilation" and predicts that Riordan will be California's Jim Jeffords. Orange County Register columnist Steven Greenhut recently threw up his hands at the prospect of a "left and lefter" race between Riordan and Democratic incumbent Gray Davis. His advice to any Republican wanting to win with Riordan: "Simply become a Democrat, and you'll be sure to be on the winning side in California for decades to come." Most ominously, CNN's "Capital Gang" on November 29 fleshed out Robert Novak's previous report that the White House has soured on Riordan. Back on November 11, Novak wrote that a California operative had told the White House that "Riordan is unfocused, unorganized and doesn't listen." On the CNN show, Novak asked Ken Khachigian, a leading California Reaganite who began speaking critically of a Riordan candidacy as early as last June, whether "the bloom is off the rose" where Riordan is concerned. Khachigian replied that Riordan "came on as this sort of great nonpartisan hope" but the White House now thinks he "probably has not quite had the experience that they thought he might have." (This, about a 71-year-old former two-term Los Angeles mayor perhaps better connected than George H.W. Bush!) Panelist Kate O'Beirne provided the clincher when she noted that California Republicans she talks to "see [Riordan] as a fairly conventional liberal Democrat in his positions. For instance, he's written that Californians are undertaxed." But Riordan has also done a lot that could appeal to the right, even in the 10-year-old document alluded to by O'Beirne--not that he's done much to point it out. On November 4, Sacramento Bee columnist Daniel Weintraub gave readers a pop quiz: Which Republican gubernatorial candidate helped lead the campaign to oust soft-on-crime California Chief Justice Rose Bird in 1986; wrested control of the state's largest school district from a board dominated by the teachers' unions; referred to welfare program officials as "poverty pimps"; and subscribed to the credo that "the highest level of giving is teaching people to be self-sufficient"? Riordan did all of these things, and more, but he's not talking about them. When he officially launched his campaign on November 6, he did so in the company of Arnold Schwarzenegger and several friendly Democrats along Los Angeles's historic Olvera Street--and never mentioned he's a Republican. He did attack Gray Davis, however, and ever since he's acted as if Davis were his only opponent. If not for the dutiful candidacies of Republicans Bill Jones and Bill Simon Jr., one would be hard pressed to remember that Riordan will first have to win the GOP primary scheduled for March 5. Without a stronger effort to prove his Republican bona fides, party insiders warn, Riordan might have trouble just doing that, let alone winning the support of the conservative base in November. He is lucky in his friends, however. One of them, Shawn Steel, the likable California state GOP chairman and movement conservative, appeared in Washington last month before conservative activist Grover Norquist's Wednesday group and spoke glowingly of both Simon and Riordan. Word quickly got back to California that Steel had played up Riordan's record as tough on crime, unions, and even taxes and said Riordan "has the best chance to win [the nomination] as of now." Steel did concede that Riordan lacks a Reaganite vision. "Dick is a personality guy, not ideological," he later explained. Or as Riordan told Weintraub, "People in Los Angeles know that Dick Riordan is a Republican. But I think what the people in California want, and the people in L.A. wanted, are nonpartisan problem-solvers, somebody who is going to be a leader for Republicans, Democrats, independents, and everybody else. That describes Dick Riordan." That's good enough for Rep. Dana Rohrabacher, the Orange County conservative and early Riordan backer who calls his man "a 50 percent guy," as in, you'll like half of what he stands for. By Rohrabacher's reckoning, that's a whole lot better than Gray Davis, whom he calls "a 20 percent guy." Other supporters repeat the 50 percent point. Still, they see Riordan as the only Republican with a chance to beat Davis. A different set of numbers tells the story: In California, registered Democrats outnumber registered Republicans by nearly 1.7 million, or by 45 percent to 35 percent of the registered electorate. Riordan won twice in a city where Democrats outnumber Republicans by nearly three to one. Conservative attacks on Riordan usually manage to ignore those numbers. But there's no getting around them. With Riordan there are other compensations, like his personal qualities. Claremont McKenna College political scientist Peter Skerry calls him "the original inclusive Republican." Alan Alda and Susan Estrich belong to Riordan's book club, but so does James Q. Wilson. His philanthropic commitment to inner-city schools well predates his elective career. Skerry, author of "Mexican Americans: The Ambivalent Minority," recalls first hearing good things about Riordan from L.A. Hispanic contacts long before he heard of Riordan the politician. It's no accident that Riordan was reelected in 1997 with over 60 percent of the Latino vote. Ron Unz singles out Riordan for the political independence and imagination he displayed in 1998 backing the Proposition 227 effort to outlaw bilingual education, a campaign highlighted by a televised ad paid for by Riordan and narrated by his daughter--in Spanish. Rep. Doug Ose, northern California finance chair for the Riordan campaign and a member of the moderate Republican Main Street Partnership, sees a Reaganite parallel. Riordan, he says, "clearly appeals to a broad and diverse group. That's how Reagan won, and that's how we'll win." And maybe he will--but he has to win the Republican primary first. Wladyslaw Pleszczynski is a distinguished visiting fellow at the Hoover Institution.