When California Gov. Gray Davis's mother read the article in last week's Time magazine hailing him as "the most courageous governor in America," she faxed him a congratulatory message saying she was so proud, "I'm considering becoming a Democrat." It was a family joke, but Davis was only half-kidding when he faxed her back urging her not to change her party registration. His Republican parentage has been part of his armor against suspicions that Davis, who came to Sacramento a quarter-century ago as former governor Jerry Brown's top aide, is -- ugh! -- a liberal.

The Time story was Topic A in Sacramento last week, but the reaction of politicians and journalists was more derisive than that of Davis's mom. Many agreed with Sacramento Bee columnist John Jacobs's judgment that "calculating" might have been more accurate than "courageous" in the Time headline.

Whatever the right adjective, the fact is that the first Democrat to govern this mega-state in 16 years has rewritten the script in ways that will be felt not just in California but in national politics as well.

As he labored last weekend against a midnight Sunday deadline, deciding which of the hundreds of bills sent to him by the Democratic Legislature to sign or veto, Davis told me he had "followed a middle path and really moved mountains on issues that have befuddled previous governors and legislatures." He cited enactment of laws on HMO patients' rights, gun control, gay rights and school reform, early passage of the budget, a negotiated agreement on Indian gambling and a settlement of the contentious litigation over the initiative that denied state services to illegal immigrants. Later, he approved significant measures for low-cost auto insurance and full staffing of hospitals.

But in the next breath, Davis bragged that he had stiffed his longtime allies in organized labor on a workers' compensation bill and vetoed a bill sponsored "by one of my best friends in the Legislature" to limit construction of "big box" discount stores. On Sunday he also vetoed bills to stiffen regulation of nursing homes and re-examine the costs and benefits of "three strikes" sentencing laws, once again frustrating the hopes of liberal constituencies who dreamed that finally having a Democratic governor would let them enact their whole agenda.

Instead, Davis has taken on the role of traffic cop, admonishing impatient Democratic legislators (all feeling the pressure of term limits) to slow down and look where they are going.

The strategy has made Davis the undisputed strongman in the nation's second-biggest government. By demonstrating his willingness to counteract the most vocal and powerful interest groups of the left, by insisting that the Legislature water down the patients' protection bills, for example, or by vetoing a bill to ban racial profiling by police, Davis has stripped the Republicans of issues -- and made himself indispensable to business lobbies.

"He is the only game in town," the head of one of the state's biggest trade associations told me, explaining why business "won't give money to the [California] Republican Party," currently led by adherents of the Christian right, while helping Davis raise almost $6 million for his personal campaign fund in the first nine months of his four-year term.

In all likelihood, business lobbyists say, California companies will refuse to back next year's ballot initiative, devised by Republican Rep. Bill Thomas of California, to cut the Legislature's pay and strip it of power to redistrict the state after the 2000 Census. National Republicans fear -- with good reason -- that a redistricting plan written by the Democratic Legislature and signed by Davis could cost them enough seats in the House of Representatives to keep them in the minority for the following decade. But business cares less about that than about keeping the good will of the governor.

There's also an important implication for the Democrats. Davis is the most prominent supporter of Vice President Al Gore in what looms as a crucial showdown against former New Jersey senator Bill Bradley in the March 7 California presidential primary. To the extent that Davis has padded his record by playing hardball against core Democratic constituencies and interest groups, he jeopardizes Gore's activist support.

The leader of one important Democratic-aligned organization, whose national board already has endorsed Gore, made a biting comment about the Gore campaign's frequent references to California as "the fire wall" that will stop any momentum Bradley gains in the New Hampshire primary. "It takes work to build a fire wall," this man said, "and if the call to build one for Gore comes from Gray Davis, a lot of us may just say we're busy with other things."