By Caren Bohan and Rachelle Younglai
WASHINGTON (Reuters) - Republican U.S. Senator Marco Rubio, who is considered crucial for the success of an immigration law overhaul, on Tuesday vowed to fight for a biometric system to track foreigners leaving the country after a Senate panel rejected the provision, in part because it was too costly.
Rubio and seven other Republican and Democratic senators, known as the "gang of eight," have crafted a sweeping bill that would revamp the immigration system, increase work visas and put millions of illegal immigrants on a path to citizenship.
In its second day of examining the legislation, the Senate Judiciary Committee voted against the Republican amendment that would have made it easier for the government to track illegal immigrants and other foreigners who have overstayed their visas.
The amendment would have required a biometric system, which uses technology such as iris scans and fingerprinting, at every point of entry in the United States before illegal immigrants would be eligible for permanent residency or a green card.
Citing a $25 billion price tag and saying it would delay citizenship for the unauthorized foreigners, two of the Republicans who helped craft the bill sided with Democrats to defeat the amendment 12-6.
In an effort to keep the legislation intact, the bipartisan gang of eight senators agreed to work together to block amendments that could kill the bill.
But Rubio's office said he was disappointed by the vote and would fight to add biometrics to the exit system when the bill is considered by the full Senate later this year.
"Having an exit system that utilizes biometric information will help make sure that future visitors to the United States leave when they are supposed to," his spokesman said.
Immigration reform advocates hope Rubio's popularity with conservatives will help sell the bill to his party.
The committee has already succeeded in rejecting other Republican attempts to beef up border security in ways that go beyond the bill and could jeopardize the path to citizenship.
On Thursday, lawmakers were due to consider changes to work visa programs and were under pressure from businesses to make it easier to recruit highly skilled workers from other countries and bring in more foreigners to do manual labor.
High-tech companies and other businesses are pushing for changes to provisions that would require firms to seek American applicants first for any job and that would prohibit the displacement of U.S. workers. The companies are backing a series of amendments by Republican Utah Senator Orrin Hatch concerning the skilled worker visa program known as H1-B.
The AFL-CIO labor organization opposes the amendments, saying they would be unfair to American workers.
The committee delayed some of Hatch's most controversial amendments to give lawmakers time to hash out a compromise.
Hatch, whose support is important because it would increase pressure on the Republican-led House to work on legislation, said he has had conversations with the Senate gang of eight and has made clear the H1-B visa issue may be pivotal to his vote.
"I think they're taking me seriously. Let's put it that way," Hatch said of the Senate gang. "And I hope they do because if they don't, I'm not going to support this bill."
As the committee debated changes to the nearly 900-page bill, a group of conservative Republicans in the House of Representatives vowed to "tear up" and defeat that bill if it reaches their chamber.
They derided the Senate legislation as little more than "amnesty" for those who have come to the United States illegally or overstayed their visas. If enacted, they said it would cost U.S. taxpayers trillions of dollars.
Representative Steve King of Iowa told reporters that House conservatives were launching a public relations campaign consisting of floor speeches, opinion articles and other actions to "get the message out that there's another viewpoint here. It's not the one that's being stampeded in the Senate and may be stampeded in the House."
Representative Steve Stockman of Texas, referring to the eight Republican and Democratic senators who wrote the Senate's immigration bill, said, "They have a gang of eight. We're going to have a gang of millions" who, Stockman said, "will rise up against" the bill.
Instead of comprehensive immigration reform, these House conservatives want new steps to secure the southwestern U.S. border against illegal crossings before considering other changes to immigration law.
(Reporting by Caren Bohan, Rachelle Younglai and Richard Cowan; Editing by Vicki Allen and Andrew Hay)