SACRAMENTO — Long exiled to the shadows of society, illegal immigrants have emerged this year as never before as a topic of intense and sometimes ugly debate under the Capitol dome.

Prodded by the slumping California economy and the belief that undocumented immigrants are draining the state treasury, a zealous group of Sacramento lawmakers is carrying an uncommonly large slate of legislation designed to make the state less hospitable to such newcomers.

Mostly conservative Republicans from the suburbs of Los Angeles and Orange counties, they have been pushing nearly two dozen bills--everything from a ban on undocumented children in public schools to a prohibition on driver's licenses for illegal immigrants. Last year, there were only two such measures.

Gov. Pete Wilson has also waded in. He has backed one controversial bill in hopes of symbolically boosting efforts to capture federal money to defray the cost of illegal immigration.

"This is the hottest button going," said Assemblyman Gil Ferguson (R-Newport Beach), who sponsored two of the bills. "As people hear about job losses and the state deficit, the backlash against illegal aliens grows."

Although the bills' authors say they are reacting to the complaints of constituents, critics contend that the burst of attention springs from political opportunism--namely, a desire to use the issue in upcoming campaigns.

During last year's elections, tough talk on illegal immigration became a standard stump speech for many Republican candidates and a few Democrats.

The legislative success of the measures seems for some lawmakers to be less important than being seen as doing something about the volatile issue.

Although Republicans take pains to say they are not targeting Latin American immigrants, some Democrats charge that the move has a racist element aimed at Latinos.

Assemblyman Richard Polanco, a Los Angeles Democrat who captains the Assembly Latino Caucus, has fended off most of the legislation so far. Polanco is supported by liberal lobbyists and Latino activists who pick apart the proposals as illegal, ill-conceived and unworkable.

Several bills have been killed in committees controlled by Democrats, who contend that the issue is a federal problem. They say illegal immigration cannot be stemmed until there is more development in Mexico and until U.S. employers stop seeking cheap labor. Polanco and his colleagues have also launched a counteroffensive, sponsoring bills that would ease the burden on immigrants and speed the naturalization of arrivals.