BURLINGAME - Between 1980 and 1990, Republicans won eight of the 10 top-of-the-ticket political contests - those for president, governor or U.S. senator - in California. But in the following decade, 1990-2002, there was a dramatic reversal of fortunes, with Democrats winning 10 of 11 high-profile partisan duels.

Those numbers illustrate the cyclical pattern in California politics. The state is rock-solid for neither party and tends to shift its partisan orientation periodically, driven by its own ever-changing demography and the primacy of key issues. If anything, the potential for such partisan swings is increasing because the proportion of voters who identify - through their voter registration - with either of the major parties has been declining steadily, with Democratic registration suffering a much-larger decline. While Democrats still lead, the ranks of independent voters have been increasing and today account for nearly 20 percent of registration - and the gap between the parties is the smallest in decades.

California voters demonstrated their fickleness last year by ousting Democrat Gray Davis from the governorship less than a year after re-electing him, and replacing him with Republican Arnold Schwarzenegger by a wide margin.

Could California be ready for another of its decennial swings of political orientation? Are Democrats, who just 16 months ago swept every statewide office, now in decline, and have Republicans, who have been losing almost everything of late, hit bottom and begun to rebound?

When the state's Democratic Party staged its annual convention in San Jose a month ago, the mood was edgy at best. The party's leaders and its powerful internal interest groups were worried about the Schwarzenegger effect on their recent hegemony, uncertain whether Davis' recall was an isolated event, sparked by his own off-putting personality and passive approach to governance, or whether it represented a broader revolt against the Democrat-dominated status quo.

In stark contrast, the mood at the past weekend's state Republican convention was upbeat, celebratory and, for a change, unified. Republicans put aside the squabbles over ideology that have often marked their conventions, and embraced a governor who may have an "R" after his name, but who is ideologically the least conservative GOP governor since Earl Warren.

Schwarzenegger spent only a few hours in Burlingame before jetting off to a national governors conference in Washington, but he received thunderous applause as he ticked off his very ambitious legislative program and promised that "We will never abandon our principles in order to cut a deal."

Schwarzenegger's command of the party was underscored Sunday when the mostly conservative delegates, with scarcely a murmur, endorsed two Schwarzenegger-sponsored ballot measures, Propositions 57 and 58, that include a $15 billion bond issue to refinance the state's immense budget debt.

"It will be a whole new ballgame, trust me," Schwarzenegger said, adding, "Government can change because people can make it change."

One senior Republican legislator summed up the euphoria that has patched over the party's ideological divisions on abortion, gun control and other gut-level issues this way: "There's nothing like winning."

The Republicans' shift of focus actually predates the recall and the rise of Schwarzenegger. The takeover of the party's financial apparatus - over the objections of rigid conservatives - by forces close to the Bush White House and the elevation of the relatively moderate Duf Sundheim into the state chairmanship had preceded last year's events. And Republicans actually gained three legislative seats in Democrat-designated districts in 2002.

Do these events foretell a greater partisan shift? Certainly Schwarzenegger's election bolsters minority Republicans in the Legislature, and strategists in both parties believe that the GOP stands a good chance of gaining a few more legislative seats this year. But Democratic U.S. Sen. Barbara Boxer is favored to win re-election, and President Bush is not favored to win the state's electoral votes.

The objective view is that Republicans have halted their decline and Democrats are no longer in ascent. Once again, California is in partisan play.