By Gabriel Debenedetti
WASHINGTON (Reuters) - A year after falling out of favor with fellow conservatives over his push to reform the U.S. immigration system, one-time Tea Party golden boy Marco Rubio is rebuilding bridges with activists on the Republican right who could smooth his way toward a possible White House run in 2016.
Rubio's office is working on economic policies with the influential Heritage Action for America group, which fiercely criticized a bipartisan bill last year partly written by Rubio that would have relaxed immigration laws.
And the first-term U.S. senator from Florida appears to have made up with Tea Party patriarch Jim DeMint, a one-time mentor whose criticism also helped sink the immigration bill.
DeMint, a former senator from South Carolina, leads the Heritage Foundation think tank, which often helps shape the right-wing policy agenda and is affiliated with Heritage Action.
Rubio's warmer ties with high-profile Tea Partiers do not mean he has regained his position as a star with the Republican Party's right wing. But they do appear to be part of an attempt to move on from his setback on immigration and shore up some conservative support in a crowded field of possible right-wing Republican candidates.
Although they have received more attention recently, Rubio's potential conservative rivals in the presidential race, like senators Ted Cruz and Rand Paul, have yet to really break out as candidates, said Republican strategist Ford O'Connell.
That could leave some room for Rubio, a Cuban American, to win over conservatives and redeem himself for what many Tea Party supporters in 2013 saw as his backing for amnesty for illegal immigrants.
"It is no secret we vehemently disagreed with Senator Rubio on amnesty, but the conservative movement is - and the Republican Party should be - large enough for fact-based policy disagreements among friends," Heritage Action leader Mike Needham said.
"Heritage Action maintains a very productive working relationship with the Senator and his staff - a relationship that existed before and endured throughout the immigration debate."
Needham's group described the immigration reform plans as "false promises" in May 2013, and compared them to President Barack Obama's healthcare and financial regulation overhauls, both of which were despised by the right and which helped fuel the growth of the Tea Party movement of small government and fiscal conservatism.
FRIENDS WITH TEA PARTY KINGMAKER
DeMint said in September that Rubio's immigration work had hurt him politically.
Rubio said he has also kept his close ties to DeMint and says he speaks to the Tea Party kingmaker frequently. "I see him quite often. We remain very good friends," Rubio told Reuters.
The senator's rekindled relationship with Tea Party leaders seemed unlikely as recently as March, when Rubio's standing among presidential contenders in the Conservative Political Action Conference straw poll of activists dropped to seventh from a close second the previous year.
But Rubio has recently promoted his vision of a robust U.S. foreign policy and has given speeches about favored Tea Party themes such as economic mobility for the middle class and cuts to government spending. He said he is weighing whether to introduce an education financing proposal as an individual bill in Congress.
Rubio, who was elected to the Florida House of Representatives when he was just 28, says he will not decide on a presidential run before midterm elections this November, but in the meantime he projects ambition.
Asked in an interview aired on Sunday on ABC's Program "This Week" if he thinks he is ready to be president, Rubio said "I do," noting that even though he is just 42 he has held public office for about 14 years.
Rubio's presidential dreams could depend on former Florida governor Jeb Bush, who would likely soak up Rubio's home-state support and money if he were to run. Bush said last month he would decide on whether to run after the November congressional elections.
Rubio said he and Bush "email often" about policies, though they do not talk politics. He would not go into detail about the content of their communications.
Beyond his fence-mending with the right, Rubio has been raising money for groups aligned not with the Tea Party but with the Republican establishment, such as party committees and Karl Rove's Crossroads organizations.
And a pair of Rubio-affiliated committees have been paying noticeably for consultants and campaign services in South Carolina, a key early voting state in presidential elections.
The Rubio Victory Committee and Rubio's Reclaim America PAC group spent over $70,000 in South Carolina in the first quarter of 2014, according to campaign finance filings.
Building a large presence in South Carolina early on could help a presidential contender, said Tim Scott, a U.S. senator from the state. He said Rubio was "well received" in the state.
Republican strategist O'Connell said Rubio's chances as a presidential hopeful are under-rated.
"The rest of the field both on the establishment side and the conservative side is faltering. Cruz hasn't demonstrated the ability to get beyond the base and Rand Paul's foreign policy has him crosswise with the establishment. So right now Rubio is undervalued as a 2016 candidate," he said.
(Reporting by Gabriel Debenedetti; Editing by Alistair Bell and Frances Kerry)