By Caren Bohan
WASHINGTON (Reuters) - Paul Ryan, the Republican congressman and former vice-presidential candidate best known for his war on spending, is emerging as his party's leading champion of immigration reform in the U.S. House of Representatives.
With Senate passage of a sweeping immigration bill imminent, Ryan has been meeting with House conservatives to persuade them that reform of the immigration system, including a path to citizenship for illegal immigrants, is an economic necessity and critical to fixing the nation's fiscal problems.
Ryan, a potential 2016 presidential contender, sees himself as a "bridge builder" between immigration advocacy groups and reluctant Republicans, he said in an interview with Reuters.
He argues that the immigration system is broken and must be overhauled. "It doesn't work for national security. It doesn't work for economic security," Ryan said.
While bi-partisan support is propelling comprehensive immigration reform in the Senate, the Republican-controlled House will take a piecemeal approach, with passage of any "pathway to citizenship" a longshot, at best.
Supporters believe the 43-year-old lawmaker, who hails from a moderate district in southern Wisconsin, two hours north of Chicago, can make a difference because of his stature as a leading conservative voice and a possible White House candidate.
Anti-tax activist Grover Norquist said the sheer amount of time Ryan has spent talking with House Republicans about budget issues gives him the credibility to court them on immigration reform.
"I would bet you a nickel that he has had more face time with each member than anyone else in the caucus," said Norquist, an influential conservative who also believes immigration reform is vital to the economy.
Republican strategist Whit Ayres calls Ryan "one of the most effective messengers the Republican party has in the House," adding that "If Paul Ryan talks, the House Republicans will listen."
That assessment may be overly optimistic, considering the large number of House Republicans from conservative districts who see legalization of illegal immigrants and offering them a path to eventually become U.S. citizens as an "amnesty."
But Ryan said a Republican-backed amendment to the Senate bill to boost security on the U.S.-Mexico border improves the chances that the House and Senate could ultimately agree on a compromise version of the legislation.
The amendment "brings the Senate bill closer to the House's position and that gives me the belief that we have a better chance at getting this law fixed at the end," he said.
Unlike Republican Senator Marco Rubio, an architect of the Senate immigration bill and a potential rival for Ryan if both seek the presidency, Ryan is not writing legislation or participating in a congressional working group on the issue.
But both Ryan and Rubio face risks from the divisiveness of the immigration issue among Republicans.
Support for immigration reform could cost either man votes with conservatives who will nominate a 2016 Republican candidate. On the other hand, the influence of Hispanic-Americans in U.S. elections could make it harder for any candidate who opposes immigration reform to win the White House.
Mitt Romney, who chose Ryan as his running mate in 2012 to shore up his conservative credentials, won less than 30 percent of the Hispanic vote, prompting Republican leaders to re-think the party's traditional wariness of immigration reform.
Should Ryan run in 2016, his support for immigration reform will distance him from Romney's position during the campaign that illegal immigrants ought to "self-deport."
Pressure on Republicans from shifting demographics are evident in Ryan's own Wisconsin district, which has the second largest Latino population among the state's districts.
But Ryan is not a new convert to immigration reform and he says politics are not driving his embrace of it. His work on it goes back to his days as an aide to Jack Kemp, the late congressman who saw immigration as part of a free-trade agenda.
In April, Ryan teamed up with his friend, Democratic Congressman Luis Gutierrez, who is a staunch supporter of immigration reform, to tout the issue at an event in Chicago. He has also co-sponsored immigration reform bills in the past.
Like Rubio, the son of Cuban immigrants, Ryan talks of the work ethic of immigrants and the high proportion who start businesses. He often tells of his Irish ancestors who fled the potato famine in the 1850s and started a family farm in Wisconsin.
In the interview, he cited future budget deficits as a reason for urgency on immigration reform. With 10,000 baby boomers retiring from the workforce each day, "our economy is going to need more labor in the future," he said.
Ryan said he believes the country needs a system "designed for the economy, to bring workers in to do jobs that people won't do or to bring their high-tech intellectual capital."
The fiscal argument helped fuel momentum for the Senate immigration bill when the Congressional Budget Office estimated it would reduce deficits by $197 billion over a decade because of additional workers paying income and payroll taxes.
If Ryan is worried about a conservative backlash on immigration, he is showing no signs of it.
He has offered to debate anyone who says an "earned" path to citizenship is the equivalent of amnesty.
And the man who has sparred for years with Democrats on budget issues believes he can play a role in getting the two parties to work together. "I think when you get Democrats to listen to Republicans and Republicans to listen to Democrats you can find the common ground," he said.
Alex Nowrasteh of the libertarian Cato Institute said Ryan could give other Republicans political cover to support immigration reform. "Nobody is going to question the conservative credentials of Paul Ryan," he said.
(Editing by Fred Barbash, Mary Milliken and Tim Dobbyn)