By Richard Cowan and Thomas Ferraro
WASHINGTON (Reuters) - The U.S. Senate approved a landmark immigration bill on Thursday that would provide millions of undocumented immigrants a chance to become citizens, but the leader of the House of Representatives said the measure was dead on arrival in the House.
In a rare show of bipartisanship, the Democratic-controlled Senate passed the bill by a vote of 68-32, with 14 of the Senate's 46 Republicans joining all 52 Democrats and two independents in support of the bill.
But any air of celebration was tempered by House Speaker John Boehner, who hours before the vote emphasized that Republicans would "do our own bill," one that "reflects the will of our majority," many of whom oppose citizenship for immigrants who are in the United States illegally.
Any bill in the Republican-controlled House is expected to focus heavily on border security and finding immigrants who have overstayed their visas.
"Immigration reform has to be grounded in real border security," Boehner said.
Republican divisions over immigration were evident throughout the U.S. Capitol. While Boehner was putting the brakes on the Senate bill, Republican Senator Marco Rubio of Florida, a possible 2016 presidential candidate, delivered a passionate speech urging passage of the measure that he helped write.
After recounting his parents' difficult lives in Cuba and their struggles after immigrating to the United States, Rubio said: "For over 200 years now, they (immigrants) have come; in search of liberty and freedom, for sure. But often simply looking for jobs to feed their kids and the chance of a better life."
At the end of the Senate debate, a packed gallery of supporters, who have labored decades for such a moment, witnessed the vote that came after three weeks of sometimes heated discussion. More than 100 children of illegal immigrants who were brought to the United States by their parents hugged each other when the bill passed.
President Barack Obama, praising the bill, said it contained tough border security requirements and "earned citizenship" for about 11 million undocumented residents.
"Today, the Senate did its job. It's now up to the House to do the same," Obama said in a statement.
Mexico's Foreign Ministry said in a statement that the Senate bill "has the potential to improve the lives of millions of Mexicans living in the United States today."
The Senate vote came after several unsuccessful attempts in the past decade or so to overhaul a U.S. immigration law enacted in 1986. The goal has been to improve an outdated visa system and help U.S. firms get easier access to foreign labor ranging from farm and construction workers to high-skilled employees.
Business and labor groups reached a deal on the new visa system, which is part of the Senate bill. But controversy raged over how much new border security was needed and how long the 11 million should wait before becoming legal residents and then citizens.
As the Senate wrapped up its debate, Senate Majority Leader Harry Reid recounted the story of a 4-year-old girl, Astrid Silva, who illegally crossed into the United States with her family in a rubber raft 21 years ago.
"This bill paves the way for people like Astrid and her family - people who are American in all but paperwork - to become full participants in this society," Reid said.
Republicans have argued that Americans do not support placing the 11 million on a pathway to citizenship, or "amnesty," as they call it.
While House Democrats and some Republicans could conceivably team up to pass the Senate's measure, or one like it, Boehner repeated that he would not allow consideration of any bill that does not have the support of most of the House's 234 Republicans.
That position may make it impossible to pass a comprehensive immigration bill in this Congress, a top priority of Obama.
For months, leading Senate backers of the bill said they aimed to achieve a symbolic 70 votes for passage, a show of force they hoped would help persuade conservative Republicans in the House to rethink their opposition.
They fell two votes short on Thursday. Republican Senator Charles Grassley of Iowa, an outspoken opponent of the bill, said the failure to hit 70 votes was a strategic setback for proponents.
Republican Senator Jeff Flake of Arizona, who helped write the bill, said, "68 is a good amount" and, "We will be working the House hard" to win passage of a bill.
Many Republicans argued that the party should heal its rift over immigration legislation. Senator Lindsey Graham of South Carolina, who helped write the Senate bill, said it was difficult to get Hispanic-Americans even to listen to Republicans because many likely think they "want to deport their grandmother."
Despite earlier statements by some House Republicans that a bill could be on the floor sometime in July, Boehner declined to say when the full House might debate and vote on an immigration measure, saying that he will huddle with his fellow Republicans following a July 4 holiday recess.
One House Republican aide told Reuters the House debate might be put off until the fall.
Nevertheless, the Senate was treating the immigration bill as a measure of historic importance.
Reid, the Senate majority leader, took the unusual step of calling all 100 senators to the chamber for the vote, requiring them to cast votes while seated at their desks.
On most votes, senators mill around the chamber talking to each other, creating a noisy scene in the ornate chamber.
But Reid sought more decorum on Thursday. "This is not a vote where people should be straggling in," he said.
On Wednesday, the Senate approved a major border security amendment aimed at broadening Republican support for the bill.
It would spend $46 billion in 10 years to place 20,000 more federal law enforcement agents at the U.S.-Mexico border, finish construction of a 700-mile (1,125-km) fence on portions of the border and purchase high-tech surveillance equipment.
The Republican-controlled House Judiciary Committee is working on various immigration bills. This week it passed legislation requiring all U.S. employers to use an electronic program known as E-Verify to ensure they are only hiring legally documented workers.
The committee also is working on a bill to increase work visas for the high-tech industry and has passed other bills to strengthen enforcement and to establish a new temporary work visa for farm hands.
The Senate bill contains many of these elements, in addition to the pathway to citizenship.
"What I see myself voting for, number one, is border security," said Republican Representative Sean Duffy of Wisconsin. "We are a nation of immigrants but we are also a nation of laws."
(Additional reporting by Rachelle Younglai and Caren Bohan in Washington and David Alire Garcia in Mexico City; Editing by Fred Barbash, Cynthia Osterman and Eric Beech)