WASHINGTON -- President Bush faces a major rebellion within his party if he follows through on a promise to push legislation that would offer millions of illegal immigrants a path to US citizenship.
Almost no issue divides Republicans as deeply.
To get the guest-worker initiative through Congress, Bush will need to go against the wishes of many Republicans and forge bipartisan alliances. That is what President Clinton did in 1993 to win approval for a free trade agreement with Mexico and Canada, over objections of a large bloc of congressional Democrats.
The chance seems slim for finding common ground between those in favor of liberalized immigration laws -- Bush; Senator John S. McCain, Republican of Arizona; and Governor Arnold Schwarzenegger of California, for example -- and those who want fewer immigrants, tougher border controls, and harsher penalties.
Opposition is strongest among House Republicans.
''In our party, this is a deep division that is growing deeper every minute," said Representative Tom Tancredo, Republican of Colorado. He heads a group of 70 legislators who oppose easing immigration laws.
Tancredo said the guest-worker proposal is ''a pig with lipstick" and will not pass.
Bush insists he won valuable ''political capital" in the election and intends to spend it. It is not clear how much of that he is willing to spend on the immigration measure.
Higher on his list of priorities is overhauling Social Security, rewriting tax laws, limiting lawsuit judgments, and making his first-term tax cuts permanent.
An estimated 10 million immigrants live in the United States illegally; the vast majority are from Mexico, and an additional million arrive every year.
A hint of the trouble ahead for Bush on immigration surfaced this month when proposals to tighten, not ease, border restrictions nearly undermined a bill to restructure US intelligence agencies.
The chairman of the House Judiciary Committee wanted the measure to bar states from giving a driver's license to illegal immigrants. Representative F. James Sensenbrenner Jr., Republican of Wisconsin, said some of the Sept. 11, 2001, hijackers gained access to US aircraft by using a driver's license as identification.
Sensenbrenner backed down, but only after House Speaker J. Dennis Hastert, Republican of Illinois, promised that the chairman's proposal would be considered in separate legislation in 2005.
Hastert also indicated that he would not move ahead on major legislation unless it was supported by a majority of Republicans in the GOP-controlled House and that he would not rely on Democratic support to pass a bill.
Immigration overhaul is ''an issue that splits both parties, and given the new Hastert rule, may never go anywhere," said William A. Niskanen, chair of the libertarian Cato Institute. Niskanen was a member of President Reagan's Council of Economic Advisers.
Bush's plan would grant temporary-worker status, for three years to six years, to millions of undocumented workers. It also would make it easier for the workers to get permanent US citizenship.
As governor of Texas, Bush was committed to immigration changes. As president, he came close to making a deal with President Vicente Fox of Mexico in the days before the attacks of Sept. 11. Those plans were put on hold as tighter borders took on a higher priority for the United States.
As a presidential candidate, in 2000 and 2004, Bush courted Hispanics, the fastest-growing ethnic group in the electorate.
''We will keep working to make this nation a welcoming place for Hispanic people, a land of opportunity 'para todos' [for all]," Bush told the League of United Latin American Citizens last summer.