SACRAMENTO — As mayor of San Diego, Pete Wilson sent local police to stop thugs from preying on illegal immigrants streaming across the border from Mexico.

As U.S. senator, he insisted on a program that eventually allowed the legal migration of more than 1 million foreign workers.

As gubernatorial candidate, he railed against illegal immigration and rode the Proposition 187 bandwagon to victory.

During the past three decades, few elected officials have steeped themselves so deeply in the immigration issue--or staked so much on it. And now, as a Republican presidential hopeful, Wilson has been thrust on the defensive amid accusations that an undocumented maid was employed in his own home 17 years ago.

Although the governor's advisers dismiss the hiring as ancient history and of no real consequence, the controversy has put a harsh spotlight on his handling of an issue that is part of the social and economic fabric of the region. And critics have seized on the episode to attack Wilson's immigration stands as politically opportunistic and hypocritical.

"It's the classic Republican Party in San Diego," said California Democratic Party consultant Bob Mulholland. "At home and in their hotels, they have nothing but illegals, but at press conferences they denounce the Democrats and illegals."

Wilson, still recovering from surgery to remove a nodule from his vocal cords, was not available for comment. But the governor's aides say he has been unwavering and tough on the immigration issue. "Pete Wilson is viewed as a national leader on illegal immigration and reforming the system," said Wilson's communications director, Leslie Goodman.

An examination of his record shows that Wilson has frequently called the federal government to task for its failure to stop the flow of illegal migrants into the country.

Documents and interviews also show that he has long championed the legal importation of low-cost labor, principally Mexican workers considered essential to the agricultural and other business interests that have supported his political career.

For example, when federal action threatened to slow permits for immigrant farm workers in the mid-1980s, then-Sen. Wilson whipped off a letter to the President and prodded officials of the Immigration and Naturalization Service.

Wilson also has resisted efforts to penalize the employers who hire undocumented workers, arguing that those efforts are ineffectual and have created a cottage industry in the counterfeiting of documents.