The measure still faces many hurdles to becoming law and significant opposition in both chambers of Congress, but its progress on March 16 makes it increasingly likely that the Republican Party will be forced into an election-year showdown over immigration policy.

An existing program called H-2B lets 66,000 foreign nationals work in landscape-related industries in the U.S. Industry leaders say tens of thousands of more legal guest workers are needed.

The guest-worker measure appeared to have solid support. “The votes are there,” said Sen. Charles E. Grassley (R-Iowa), who opposes giving permanent status to illegal immigrants.

Immigration Divides Republicans

In the House, where a large and vocal group of members says a guest-worker plan would only draw more illegal workers to the United States, legislation was approved last year that focused almost entirely on securing the nation’s borders and toughening enforcement of illegal hiring. The legislation created no new mechanisms for illegal workers to gain permanent status or for foreigners to become guest workers.

In the Senate, however, many members believe an enforcement crackdown should be paired with measures allowing employers to hire foreign workers legally, an idea that many business groups say is vital to the smooth functioning of the economy. President Bush has been pushing for a guest-worker program for two years.

The prospects in the Senate are more uncertain for the deal to create a pathway for some of the nation’s illegal immigrants to gain permanent status and citizenship. Still, supporters said the compromise significantly boosted chances for approval.

Business Depends on Immigrant Labor

Joe Colace, a produce grower, packer and shipper in Brawley, Calif., said he could not find enough pickers to harvest his lemon crop in Imperial County in December.

He typically runs eight crews of 25 to 30 workers each, he said, but last year he had to make do with five to six crews of 18 to 20 workers.

“We could not stay up with demand and we were losing ground on a daily basis,” Colace said. “The risk is already great enough without having to worry about having enough employees to harvest the crop.” The lemons he lost in the fields, he said, cost his company, Five Crowns Marketing, about $100,000.

Colace said he and other growers always tried to hire American workers, but often came up short. Last year he submitted a request for 108 workers to his local unemployment agency, he said, and got two workers in response.