A compromise immigration proposal crafted by a bipartisan group of senators seems to be hanging by a thread. Before the Memorial Day break, floor debate was heated as lawmakers considered amendments to make the proposal more palatable to its many critics. More of the same is expected when Congress returns on June 5 from a week-long recess.

The Senate approved the New Mexico Democrat's amendment to the immigration bill to halve the number of workers eligible for temporary visas. Bush administration and construction industry officials criticized the amendment. They favor an increase in the number of visas if the market requires it.

One sticking point appears to be the temporary-guest-worker program, whose opponents include many Democrats and the AFL-CIO. One critic, Barbara Boxer (D-Calif.), argues that a guest-worker plan “will lead to more illegal immigration and downward pressure on wages.”

Boxer and Byron Dorgan (D-N.D.) failed to push through amendments eliminating or “sunsetting” the guest worker program. But the Senate did approve a proposal from Jeff Bingaman (D-N.M.) to cut the number of workers eligible for temporary visas from 400,000 to 200,000, a move that was quickly criticized by the Bush administration and industry groups.

Commerce Secretary Carlos Gutierrez said that Bingaman’s amendment would eliminate a key part of the administration’s plan, which calls for 400,000 guest worker visas but with an increase to 600,000 if market conditions demand it.

Brewster Bevis, Associated Builders and Contractors’ director of legislative affairs, says removing the market-based escalator would be “very detrimental” to the construction industry, which typically requires varying numbers of workers depending on market conditions. “In the original underlying bill, the number was based on the need for workers in a particular industry and could move up or down,” Bevis says.

Associated General Contractors’ CEO Stephen Sandherr calls the Bingaman amendment “short-sighted” and contends that it “chokes off legal means to meet employment shortages.”

Even if a bill gets through the Senate, it faces tougher opposition in the House, where some Republicans have denounced it as an “amnesty” measure. Bevis says some lawmakers in that chamber “do not support any sort of comprehensive reform whatsoever, so it will be a difficult fight when it gets over to the House.” Speaker Nancy Pelosi (D-Calif.) has told the administration she won’t bring the bill to the floor until it has at least 70 Republican supporters. She said, “I have serious concerns about some elements of this proposal. The bill must be improved in the Senate,” she says.

President Bush backs the Senate compromise. “If you want to kill the bill, if you don’t want to do what’s right for America, you can pick one little aspect out of it, you can use it to frighten people,” he said. “Or you can show leadership and solve this problem once and for all.”