As Mayor Giuliani looks over the acres of gleaming tractors, mammoth cotton harvesters, and high-tech cow milking equipment at a fair in California’s vast agricultural heartland tomorrow morning, he will surely feel like he’s a long way from Manhattan.

The prospect of a visit from the man billed as America’s mayor already has local folks in California’s central valley atwitter. “Honestly, this is probably the biggest name we’ve had,” the chairman of the World Ag Expo in Tulare, Calif., Bruce Shannon, said yesterday.

Mr. Shannon allowed that Mr. Giuliani had “probably not run into a lot of combines and tractors” on the streets of Manhattan, but the organizer said the former New York mayor’s reputation precedes him. “Rudy’s very popular here,” Mr. Shannon said.

In the coming year, these kinds of rural visits and forays to California’s sprawling cities could become commonplace for Mr. Giuliani; the Golden State is poised to become a linchpin of his strategy for winning the Republican nomination for president.

One of the key factors pushing California to the fore of Mr. Giuliani’s agenda is Governor Schwarzenegger’s plan to move the state’s presidential primaries up to February 5 from the current date in June.

“I think it will have a big impact,” Mr. Giuliani said Saturday after addressing a state party convention in Sacramento. “You’re going to have to spend a lot of time here. That’s not so hard,” he joked.

A political analyst at the University of Southern California, Sherry Bebitch Jeffe, said the state’s large number of socially liberal Republicans and independents could give a boost to Mr. Giuliani, if he can’t win January contests in Iowa and New Hampshire.

“If he really does well in California, it could make up for stumbles in the early states, because they’re really not his strengths,” Ms. Jeffe said. “I can’t believe he won’t pay special attention to California. … He could be helped quite a bit by California moving its primary.”

In a little-noted California poll last month, Mr. Giuliani held a sizable lead over the rest of the Republican field. The American Research Group survey found that Mr. Giuliani had the support of 33% of likely Republican primary voters; a former House speaker who is mulling a bid but not formally exploring one, Newt Gingrich, was at 19%; and Senator McCain of Arizona had 18% support. A former Massachusetts governor who is painting himself as the most viable true conservative in the race, Mitt Romney, had just 3% backing. Some 22% of the 600 Republicans and independents surveyed said they were undecided.

Also fueling a possible romance between the former Gotham mayor and the Golden State is the unexpectedly warm reception he got Saturday from Republican delegates and activists, who tend to be much more conservative than primary voters. “It quite impressed me,” Ms. Jeffe said. “These guys believe he is the consummate anti-Hillary. He looks to them to be the only person who has the chance of beating her.”

In his speech, Mr. Giuliani promised determined leadership in the fight against terrorism, but he generally ignored social issues such as abortion and gay rights, where he is at odds with many in his party. Several delegates interviewed by The New York Sun after Mr. Giuliani spoke said he would get wide support despite any differences on social issues.

“I liked his take on the troops and Iraq,” a retired state employee from Solano County, Calif., Julia Thompson, said. “I think most of us have come to realize that there are emotional issues and there are real issues. A lot of the issues he didn’t talk about are ones that are not going to affect my daily life.”

A professor of politics at Claremont McKenna College, John Pitney Jr., attributes Mr. Giuliani’s popularity to the pre-eminence of the war on terror in the minds of many Republican voters.

“He’s established his machismo on that issue. That gives him a certain amount of running room on social issues,” Mr. Pitney said.

Still, it was clear at the Republican convention that Mr. Giuliani is not everyone’s cup of tea. The leader of a conservative caucus within the party, the California Republican Assembly, complained that Mr. Giuliani promised to meet the group Saturday but jilted them. “He failed to show up at our meeting that he was asked to come to and committed to come to,” the group’s president, Mike Spence, said.

The Giuliani campaign did not respond to a request for comment on the episode.

Mr. Spence said Mr. Giuliani was attempting to evade questions about his views on gay rights and abortion but would not be able to elude them during the back-and-forth of the upcoming campaign. “He still has to answer the questions,” the conservative leader said.

Mr. Spence also cautioned against reading too much into the warm reception given to Mr. Giuliani weekend. “Six months ago, everybody was falling all over Romney. It’s different when you get them all on the same stage and you have to make a decision,” Mr. Spence said.

Mr. Giuliani also cultivated California talent for his campaign team recently, hiring a former communications director for Mr. Schwarzenegger, Katie Levinson.