Farm-state Democrats late Tuesday helped defeat an effort by two of their colleagues to strip the temporary worker program from the comprehensive immigration reform bill now being debated in the Senate

Senators voted 64-31 to reject an amendment by Democratic Sens. Barbara Boxer and Byron Dorgan to strike the provision for as many as 600,000 unskilled workers to enter the U.S.

Arguing against the measure, Boxer alleged that it was designed "to keep a supply of desperate low-wage workers" and is "a way to keep our workers down, keep their wages down, keep their benefits down, keep them weak, and in my view, at the end of the day, destroy the middle class."

"If you care about our American worker, and you care about these other workers who will be exploited, you have to vote to delete this program," Boxer said.

The Boxer-Dorgan amendment is the first being considered on the Senate floor as the chamber goes into two weeks of debate split up by a week of vacation. The vote was the first in an onslaught against the bill that is being held together by a fragile coalition of unlikely partners.

Among those is Sen Ted Kennedy, D-Mass, lead sponsor of the bill and a longtime worker rights advocate. He took exception to the claims by Dorgan and Biden, noting that Boxer doesn't mind temporary workers when they are agricultural workers in her state of California.

Kennedy noted that at a recent raid at a factory in New Bedford, Mass., "workers' rights were trampled on! They were fined for going to the bathroom, docked 15 minutes of pay for every minute they were late. ... They were forced to ration toilet paper. If you close this out and make it illegal they're going to come in here and be exploited," he said.

The Massachusetts senator acknowledged that the temporary worker program may not be the one everyone would like, "but it is the one we have in this legislation."

"If you slam that door, it isn't going to work, it is not going to work. Those workers are going to keep coming in because of the magnet of the American economy."

But Dorgan, speaking on the Senate floor, argued that a number of American companies have packed up and moved abroad because of lower wages.

"They don't make any Levi's here anymore," he said, adding that Fruit of the Loom, Huffy Bikes, Radio Flyers and Fig Newton cookies are also no longer made in the U.S.A.

Dorgan's amendment is not expected to pass, mimicking action on last year's proposed immigration bill, but both he and Boxer are vowing to try other measures to drastically trim or sunset the program.

That could come in the form of an amendment by from Sen. Jeff Bingaman, D-N.M., who wants to reduce the number of guest worker visas from 400,000 per year to 200,000 per year.

Senate Majority Leader Harry Reid, D-NV, threw his support to Bingaman on Tuesday, saying, "I personally think the 400,000 ... is far too much. I don't like that. ... I didn't like it last year. I don't like it this year."

Opposition to the 1,000-page bill, which many senators complain has only just made it in final form into their inboxes, is coming from the right and left. Normal allies of comprehensive immigration reform, pro-immigrant groups and many business consortiums are looking askance at the legislation. Not one union group has voiced support for it.

Some Republicans call the bill amnesty with a renewable visa system while some Democrats oppose the proposal that makes skills and education more important than family ties.

Amendments being offered include ones by:

— Sen. James Inhofe, R-Okla., who wants to make English the official language of the United States and prevent entry if an immigrant can't pass the current English proficiency test;

— Sen. John Cornyn, R-Texas, who wants to allow federal law enforcement to use information from immigrant visa applications in investigations; and

— Sens. Patrick Leahy, D-Vt., and Robert Menendez, D-N.J., who want to give more weight to families for earning green cards.

Negotiators who hammered out the deal behind closed doors after months of meetings with Bush administration officials said they will meet each morning the Senate is in session during the debate to review the slate of amendments for the day and decide a strategy for supporting or defeating those amendments.

The negotiating group has about a dozen members and could easily be thwarted if liberal Democratic critics join opposing Republicans to pass any given measure. A number of the original negotiators have already left the group in opposition, including Cornyn, Leahy and Menendez. Still others in the group are withholding their support for now, like Georgia Republican Sens. Saxby Chambliss and Johnny Isakson.

The bill beefs up border security and employer verification, sets up a temporary worker program, legalizes the vast majority of the approximately 12 million illegals currently in the United States and sets up a merit-focused point system that still heavily weighs family connections for earning a green card.

Currently, about two-thirds of legal permanent residency cards are family-based, while one third are employment-based. Legislative experts agree that current ratio would not substantially change, though family migration is drastically curtailed. Only minor children and spouses can accompany green card holders, with a limited number of visas granted to "grandparents." Others would have to apply for their own green card.

Illegals, once they come out of the shadows and register, receive a temporary card and eventually a special "Z visa" to work indefinitely in the U.S, a process that takes a minimum of eight years. They are not required to return to their home country unless they wish to become U.S. citizens.

Conservatives call this "amnesty," but supporters like Sen. Arlen Specter, R-Pa., a lead negotiator, denies that charge.

"It's not amnesty. Amnesty is getting something for nothing. These workers have to pay a $5,000 fine. That's a pretty substantial amount for many of them," he said. Liberal critics say that the "touchback" provision, or home-country return, is not practical and would cause undo hardship on low-wage immigrants.

Conservatives also point out that the illegals, once legal, would automatically be eligible for Social Security and Medicare and would not be required to pay any back taxes, something bill supporters say is simply impossible to calculate.

Conservative Heritage Foundation President Robert Rector estimates the total cost of the bill to be in the trillions of dollars, warning, "This $2.5 trillion cost is going to come smashing into the Social Security and Medicare systems at exactly the point those systems are already going bankrupt. So the bottom line is that these individuals will make no net contribution in taxes while they are working. They will be a deficit. But when they hit retirement, they will be an astonishing cost on the taxpayer."

Reprising a highly controversial argument last year, Inhofe's amendment to make English the official language will probably be challenged by a Democrats alternative that was supported last year that makes English merely the "common" language.

The compromise deal creates a controversial point system for earning green cards. Though the system is weighted toward families, as it is now, about 30 percent of the points will be allotted for "merit" like education level and advanced skills, something that was deemed essential by many Republicans.

Sessions said Monday the 30 percent is "not enough." He praised Canada's merit-based program and said he would work to change that in the bill. On the other side of that fence, Leahy and Menendez said they would introduce an amendment to give even more weight in the green card system to family members.

The bill now seeks to clear the tremendous backlog of applications for citizenship within 18 months for those immigrants who applied before May 2005, a date that marks the introduction of the original Senate comprehensive immigration bill. Department of Homeland Security official say that should take care of some 567,000 applicants. Menendez said he will offer an amendment to take care of another 800,000 who applied between May 2005 and January 2007.

The price tag for this bill is expected to be extremely high, but sources told FOX News that the nonpartisan Congressional Budget Office will not have an estimate ready until after Memorial Day, something that could fracture the bill's already fragile support.

The Heritage Foundation's Rector warned that CBO will give only a 10-year estimate, "but on year 15, it starts to cost a fortune. On year 30, it will bankrupt the Social Security system. It is a disaster, it's a sham, and it's a deception."

Supporters of the bill have said the compromise is like a three-legged stool with each of the provisions — guest worker program, more permanent plan for 12 million illegals already here and border security — each being an unmovable leg, if one goes, the stool falls. Dorgan called that argument "a loose thread on a cheap suit." Boxer described the warnings as "idle threats."

Republican critics like Sessions are expected to filibuster the bill, and he could receive support from a number of Democrats, like freshman Sen. Jon Tester of Montana, who on Monday, voted against allowing debate to start on the bill. The Senate permitted the beginning of a multi-week debate on a 69-23 vote to proceed with amendments.

It is very much unclear if supporters can muster the 60 votes needed for final passage, expected to come sometime around June 8, 2007. And yet another hurdle will come when the House attempts to pass a product that Speaker Nancy Pelosi, D-Calif., has already signaled will look quite a bit different from the Senate product.