By Shailagh Murray
Washington Post Staff Writer

Republican lawmakers are headed for a showdown over illegal immigration, an issue that exposes a deep and bitter rift within the GOP.

The drama will unfold when Congress returns early next month and turns to finish an emergency spending bill to fund the Iraq war. The House version, approved before the Easter break, carries tough immigration restrictions, reigniting a long-simmering battle with the Senate over how to deal with the growing illegal population.

It is a conflict that President Bush scarcely needs as he tries to unite his party behind contentious Social Security changes and judicial nominations. Meeting Wednesday with Mexican President Vicente Fox, Bush promised to continue pushing Congress for a program allowing temporary guest workers. That accommodation is the opposite of what House conservatives are seeking with the crackdown on asylum seekers and state driver's-license requirements for illegal immigrants that they attached to the Iraq bill. Bush acknowledged the limits of his influence: "I'm not a member of the legislative branch," he told Fox.

The immigration debate pits one core GOP constituency (law-and-order conservatives) against another (business interests that rely on immigrant labor). One camp wants to tighten borders and deport people who are here illegally; the other seeks to bring illegal workers out of the shadows and acknowledge their growing economic importance.

Bush does not support giving driver's licenses to illegal immigrants, but he wants to address the problem of undocumented workers by expanding temporary-worker programs for the millions who are already here. The president ranks illegal immigration as one of the "big problems" he wants to tackle in his second term. White House Chief of Staff Andrew H. Card Jr. has called the issue a greater immediate threat than Social Security. "This elephant is sitting at the table right in front of us," Card said at a U.S. Chamber of Commerce meeting in January.

A recent Pew Hispanic Center survey found that the number of illegal immigrants in the United States has jumped by 25 percent in four years, to about 10.3 million. The growth has been scattered, extending into regions in the South and Midwest, which have traditionally seen little foreign influx. That has helped to transform immigration from a regional concern to a national one, as did the Sept. 11, 2001, attacks, which infused the issue with new security concerns.

"Nobody wants to pay the political price if you suddenly have a major terror incidence with illegal aliens with driver's licenses," said Dan Stein, head of the Federation for American Immigration Reform, a leading voice in the law-and-order camp. All 19 hijackers involved in the Sept. 11 attacks entered the United States with valid documents, but some committed fraud to obtain them.

Business leaders tell GOP lawmakers a different story: Congress must address a growing dependency on illegal labor as the U.S. population ages -- and as more jobs, especially at lower skill levels, go unfilled. Four days before the 2001 attacks, U.S. Chamber of Commerce President Thomas J. Donahue told members of the Senate Judiciary Committee that immigrants are "our best hope to curb chronic American labor shortages." He cited Bureau of Labor Statistics estimates that by 2008, the United States will have 154 million workers for 161 million jobs.

A group of House conservatives, led by Judiciary Chairman F. James Sensenbrenner Jr. (R-Wis.), say the measures will bring security improvements needed to prevent terrorist acts. For now, they want to deal only with that specific concern. Sensenbrenner had added the restrictions to the intelligence-restructuring bill but withdrew them in December when the Senate objected. House leaders assured him the restrictions would move on this year's first "must-pass" bill -- the Iraq spending legislation.

Sensenbrenner warned Senate Republicans when he reintroduced his measures in January that they were making a mistake by trying to use the funding bill "as a horse to get more controversial provisions enacted."

But the House move gives the Senate a green light to advance its broader immigration agenda when it takes up the Iraq bill next month. "Those are very specific," Senate Majority Leader Bill Frist (R-Tenn.) said of the House proposals, in a Fox News interview. ". . . And I think we need to look at immigration reform in a more comprehensive way."

One possible Senate amendment would offer temporary legal status to undocumented farmworkers. Broader guest-worker proposals, including the plan that Bush is advocating, also could end up in the mix.

Rancor over illegal immigration has become a staple on conservative blogs and talk radio, with much of the wrath directed at Bush. Stein, of the immigration reform group, said the president has dragged his heels on security improvements and "is not leading the American people on this issue."

The outcry may be resonating. House Rules Chairman David Dreier (R-Calif.) got a jolt during his 2004 reelection campaign, when radio hosts in his outer Los Angeles district decided to make him a "political human sacrifice" for his immigration views, Dreier said, accusing him, among other things, of advocating Social Security benefits for illegal immigrants.

"I said to myself, nobody's going to believe I want to give Social Security checks to people who are here illegally," Dreier recalls. Then he polled voters and found that people not only believed the allegation but had resolved "to never vote for David Dreier again." He won with 54 percent of the vote, a lower proportion than previous years, and has since taken a prominent role in advocating the Sensenbrenner measures, although he also supports guest-worker programs.

Critics of the House restrictions, including many Senate Republicans, say the curbs would trample states' rights and lead to more unlicensed drivers while ignoring what they believe to be the crux of the problem: the millions of undocumented people already entrenched in the workforce.

"There's a reality out there that few recognize," said Sen. Larry E. Craig (R-Idaho), author of the Senate farmworker measure. "They're all here, and they're necessary." Congress is addressing half the problem, Craig says, "if we do all the right things to protect our borders without parallel effort to create a legal workforce."

His allies on the issue of guest workers include labor groups, the Catholic Church, the Chamber of Commerce and prominent free-market conservatives such as Grover Norquist. Two possible 2008 GOP presidential contenders -- Sens. John McCain (Ariz.) and Chuck Hagel (Neb.) -- are writing immigration plans that focus on guest workers. McCain's co-author is Sen. Edward M. Kennedy (D-Mass).

House Republicans who support tighter rules say they are counting on a silent but determined "bite-your-lip caucus" to keep the focus on security. "Plenty of people feel the same way we do but are just remaining quiet," said Rep. Tom Tancredo (R-Colo.), a Sensenbrenner ally who travels the country calling for stricter immigration rules. "We're the ones on the offensive," Tancredo said. "Our agenda is advancing."

© 2005