The bill's critics, meanwhile, promised to keep fighting to kill the legislation in the Senate, and, if necessary, in the House. "It's DOA in the House," Rep. Mark Souder (R-Ind.) said at a news conference.
House Republicans passed a resolution Tuesday disapproving of the immigration bill 114-23. Democrats have said that at least 70 House Republicans would have to support a bill for it to pass there.
Senate opponents of the bill made a short-lived bid Tuesday to obstruct debate. Sen. Jim DeMint (R-S.C.) forced a step that required Senate clerks to read all 373 pages of the amendments to the bill before debate could proceed. That marathon reading was later called off by another opponent of the bill.
On Tuesday, 24 Republicans joined 39 Democrats, including California's two senators, Boxer and Dianne Feinstein, and one independent in favor of the debate; 25 Republicans, nine Democrats and one independent voted against it.
In addition to the five Democrats who switched positions to vote no, Montana's Jon Tester and Max Baucus, North Dakota's Byron L. Dorgan and West Virginia's Robert C. Byrd also voted against debate -- as they did when the Senate first took up the bill May 21.
Democrats share some concerns with Republicans. Bayh would like to see improved border-security provisions, although the bill includes $4.4 billion to spend on such measures. Tester and Stabenow object to the broad scope of the bill, and said they would prefer a focus on border security. Like almost all of the other undecided Democrats, both said they would wait to see how amendments changed the bill before they decided whether to support it.
"I just think the stuff with border security and port security is fine, but everything else in that bill from my perspective is already taken care of in current law," Tester said. "And if we can't enforce current law, how can we enforce new ones?"
Webb said his support would be contingent on the fate of an amendment he planned to offer that would give legal status only to those illegal immigrants who had been in the country for four years or longer, and would eliminate a requirement that they return home first. If it passes, Webb said, he would support the bill. "If not, I won't," he said.
McCaskill pinpointed work-site enforcement as a concern, citing a congressional study that concluded the bill would only reduce illegal immigration by 13%. She said she thought enforcement against employers would affect illegal immigration. "We don't need a new bill to do that," she said. "We just need a commitment on the part of the Department of Justice."
McCaskill and Menendez complained about the GOP provision that would limit the number of foreign family members U.S. citizens would be able to bring into the country. McCaskill also questioned the proposed point system's failure to allot many points for family ties. "The idea that we can't give points for legal American citizens to get their family into the country? That's ludicrous," she said.
Menendez said he was concerned about amendments written by the bill's Republican backers, including one that would require adult illegal immigrants seeking legal status to make a trip home within two years after the bill's enactment or face deportation.
"The tilt and tenor of amendments written by the Republican grand bargainers are becoming increasingly onerous and impractical," Menendez said in a statement.
(BEGIN TEXT OF INFOBOX)
Here are some key elements of the bipartisan Senate measure ...
* Allows illegal immigrants who were in the country as of Jan. 1 to gain "Z visas" if they pay fees and fines and pass a background check. Allows them eventually to become citizens after paying more fines, holding jobs and learning English. Heads of households would have to return to their home countries to apply for permanent resident visas, known as green cards.
* Creates a temporary-worker program that would allow as many as 200,000 guest workers per year to enter on two-year "Y visas" that could be renewed twice, provided they returned to their home countries for a year between each stint. Ends the program after five years.
* Prevents the Y and Z visa programs from taking effect until security and enforcement triggers are met, including adding 20,000 border agents, 370 miles of fencing, 300 miles of vehicle barriers and a new worker-verification system to prevent the hiring of illegal workers. Provides an immediate $4.4 billion to fund the measures.
* Creates an employment-based point system for new immigrants to qualify for green cards based on their educations and skill levels, and limits visa preferences for family members of U.S. citizens and legal permanent residents.
... and some major amendments to be considered before a final vote.