WASHINGTON (AFP) - The US Senate has easily cleared a key immigration reform hurdle, advancing a critical compromise Republican measure that would tighten security on the US border with Mexico.
The procedural vote on Monday marked an important test for comprehensive immigration reform backed by President Barack Obama. He wants it enacted this year, though the landmark legislation faces an uncertain fate in the House of Representatives.
Fifteen Republicans joined a unanimous Democratic side to end debate on the vital amendment, which would bring muscular new security measures to the southern US border including 20,000 additional agents, a total of 700 miles (1,125 kilometres) of secure fencing and expansion of drone surveillance along what is already the most militarised border in the Americas.
The controversial legislation, shepherded through the Senate by its four Republican and four Democratic authors, would create a 13-year-long pathway to citizenship for the more than 11 million immigrants living illegally in the United States.
It would also reform the work visa system in agriculture and high-technology fields, institute electronic employment verification and comprehensive entry-exit tracking, while seeking to prevent future waves of illegal immigration by making the US-Mexico border virtually impenetrable.
"We're securing the border but we're allowing those people at the back of the line to have some pathway to continue to live the American dream, the same things that we want for our sons and daughters all across the country," said Senator Bob Corker, who crafted the border deal with fellow Republican John Hoeven.
Mr Obama, who has largely stayed out of the fray but in recent weeks sought to nudge the bill forward, stressed at a White House meeting with business leaders on Monday ahead of the vote that immigration reform would give the nation's economic recovery a boost.
"Now is the time to get comprehensive immigration reform done," he said.
A coterie of conservatives however were banding together against the legislation, including Senator John Cornyn of the border state of Texas.
Mr Cornyn accused top Senate Democrat Harry Reid of running a Senate "dictatorship" by exerting unassailable control over which immigration amendments received votes in recent weeks, and attacked the Corker-Hoeven deal as "a "political fig leaf" that "will not solve the problem."
While recognising the amendment boosts border enforcement, Mr Cornyn and others said it unacceptably fails to implement border "triggers" that would only allow the full legalization for undocumented workers to begin once all the border security measures are in place.
"This bill has no teeth. This bill has $48 billion thrown up against the wall to buy the votes to say this bill will secure the border, and it will not," Senator Tom Coburn boomed.
Democrats hotly countered that the new border enforcement has no fewer than five triggers, including the requirement that the "e-verify" system be in place before any permanent residency cards are issued to legalized immigrants.
"They just won't take yes for an answer," Mr Schumer said, citing the added security measures inserted as a concession to skeptical Republicans.
"No one can dispute that the border will become virtually air tight." He said new technologies unavailable as recently as 10 years ago, like drone surveillance, would allow for far tighter operational control of the 2,000-mile (3,200-kilometer) border.
Mr Reid is pushing for a vote on the huge bill's final passage this week, and he has said he hopes to secure at least 70 votes to send it to the House with major momentum.
Monday's procedural step was approved 67-27, although the two Democrats who missed the vote support the amendment.
The amendment details US$3.2 billion (S$4.1 billion) in new equipment, including four unmanned drone systems, 40 helicopters, 30 boats, 4,595 unattended ground sensors, and hundreds of fixed and mobile camera systems.
Some lawmakers have warned it will be dead on arrival in the Republican-held House, where conservatives want to see stronger protections in place, and politicians of border states remain skeptical.
Arizona Governor Jan Brewer said it was "encouraging" to see additional security measures approved for the bill, but insisted it was too early to give her stamp of approval.
"There are still too many unknowns," Mr Brewer said.