California Gov. Pete Wilson yesterday became the first casualty of the race for the 1996 Republican presidential nomination, closing his short-lived, debt-ridden, mixed-message candidacy before it ever found a voice.

Just a month and a day after he joined the race, the two-term governor of the nation's most populous state told supporters in Sacramento that "as much as your hearts and mine tell me to fight on, my conscience tells me that to do so would be unfair to all of us."

He pledged that "this old Marine ain't about to just fade away," touching off speculation that his early withdrawal may have been, in part, a damage-control effort aimed at preserving his viability as a running mate for the eventual GOP nominee.

But the immediate causes of death were more straightforward. Wilson ran a high-overhead campaign that quickly found itself about $ 1.4 million in debt, alienated Californians from the outset and never struck a chord with the Republican electorate nationwide.

A lifelong moderate within the GOP, Wilson, 62, had moved rightward during the past year on such issues as affirmative action and illegal immigration in the hope of wooing the party's conservatives, whose greatest influence comes during the nomination process. Along the way, he apparently came to be seen as opportunistic by centrists and inauthentic by true believers.

At the time of his withdrawal, national polls of Republicans had him running in the low single digits in the 10-man GOP field, while in California polls he was trailing Sen. Robert J. Dole (R-Kan.) by a 2 to 1 ratio in primary matchups and President Clinton by nearly that much in a general election contest.

"Whatever you think about Pete Wilson, he's always been coldblooded and cleareyed about his own political prospects, but this is one race where I just don't think it was ever there for him," said Barbara Sinclair, a political scientist at the University of California at Riverside. "Too many people must have whispered too many words of encouragement in his ear, and he got carried away."

Though Wilson never made much of a dent as a candidate, a handful of his surviving rivals still found in his withdrawal an important boost to their campaigns.

Dole campaign manager Scott Reed said it "solidified our position as the front-runner. Governor Wilson went at us hard, to his credit, but he didn't get anywhere. That shows depth of support for Bob Dole."

"I think we have a better chance of winning California than anyone else," Sen. Phil Gramm (Tex.) told reporters yesterday in Washington. Gramm had already been endorsed by the Republican leaders of both houses of the California legislature, as well as two dozen other GOP congressmen and state legislators in California.

Said former Tennessee governor Lamar Alexander: "Governor Wilson's withdrawal makes this campaign a very clear choice between two respected senators and one governor with executive experience outside of Washington. My campaign is the only serious campaign about changing the culture of Washington, D.C."

Bay Buchanan, campaign manager for television commentator Patrick J. Buchanan, argued that Buchanan was best-positioned to pick up support from voters troubled by illegal immigration and affirmative action, issues Wilson had stressed.

Sen. Arlen Specter (R-Pa.) said the withdrawal "gives my candidacy a big boost. It leaves me as the only pro-choice candidate in the field and, more importantly, as the only centrist."

Said Sen. Richard G. Lugar (R-Ind.): "Pete Wilson . . . contributed a great deal to the presidential race. My campaign for the presidency will continue on its positive track."

Other candidates in the GOP field include Rep. Robert K. Dornan (Calif.), radio commentator Alan Keyes and publisher Malcolm S. "Steve" Forbes Jr.

Wilson's campaign was plagued by bad luck from the outset. He underwent minor throat surgery in April, and the longer-than-expected recuperation prevented him from giving speeches, attending fund-raisers or even soliciting money on the telephone for two months.

In addition, many California contributors resented being asked to fund a presidential campaign so soon after they gave so generously to his costly reelection victory last year over Democrat Kathleen Brown.

"A lot of guys ponied up big bucks for his reelection who really didn't like him," one California Republican said. "The presidential campaign infuriated people."

The campaign spent $ 5 million between July 1 and Sept. 15 and by mid-September was more than $ 1 million in debt. Wilson pulled out of Iowa, the site of the first caucuses, and then shook up a staff riven by personality conflicts. The spate of bad news only made the financial problems worse.

Ken Khachigian, a veteran GOP strategist and adviser to Wilson, summed up the reason for withdrawing in four words: "Money. Money. Money. Money."

Analysts in California said Wilson also underestimated the reaction to his breaking his pledge not to seek the presidency in 1996 -- a promise he'd made in the heat of his reelection campaign last year. "When he broke that pledge shortly after he was inaugurated, a lot of people who came together for the governor decided he had betrayed them," said Steve Merksamer, a California political operative. "The impact of breaking the pledge was never fully contemplated or appreciated."

Wilson also misjudged the difficulty of running for president while trying to run a state as large as California. "Governing our state is incompatible with the kind of effort that is necessary to run an effective presidential campaign," Merksamer said.

Finally, in the past month, the intense speculation over the potential candidacy of retired Gen. Colin L. Powell gave potential contributors another reason to hold off.

By ending his campaign now, rather than going into a low-gear suspension mode, Wilson may be forgoing $ 1 million or more in Federal Election Commission matching funds, which he had already qualified for but which are not awarded until next January. Campaign spokesmen said they were researching whether he would still be eligible. But they added that Wilson was anxious to make a clean break from the presidential race so he could concentrate on rebuilding his battered political and policy base for the remaining three years of his governorship.

Campaign chairman Craig Fuller said the topic of a potential running-mate slot never came up during intense discussions with Wilson over the past several days, but added: "He should be on everybody's short list."

UC-Riverside's Sinclair said she thought the short, aborted campaign had turned Wilson into damaged goods as a vice-presidential pick, but Larry Berman, a political scientist at UC-Davis, said: "By getting out early, he spared himself the scars and hits you take in a campaign. Maybe he'll look good again at the end of the process."