WASHINGTON -- Being on the losing team never felt so good. Just don’t expect U.S. Sen. Marco Rubio to acknowledge it.

“My trip to Iowa has nothing to do with 2016,” he said Thursday, a remark no one in Washington took seriously, even though Rubio pointed out the visit was set up months ago back when he expected Mitt Romney would be seeking re-election in four years.

Yet there was Rubio on Saturday evening in the state that holds the first nominating contest, giving a keynote speech at a birthday fundraiser for Republican Gov. Terry Branstad.

Absurd as it may seem — the next presidential election is 48 months away — potential contenders are taking faint steps, and Rubio has claimed his spot in the fray. Two years ago, he defied convention by winning a Senate seat on the winds of the tea party. Now he is propelled by a demographic crisis.

“It’s obvious to one and all that the Republican Party cannot put together a winning coalition by getting a larger and larger share of a smaller and smaller number of white voters,” said Rubio’s pollster, Whit Ayres. “We need to reach out aggressively to nonwhite voters, and Marco Rubio will be a key voice.”

Romney’s bitter complaint last week that President Barack Obama won by giving policy “gifts” to young women, blacks and Hispanics, underscored the challenge — and the opportunity for Rubio, 41, the son of Cuban immigrants, to represent a new generation of Republicans.

The party has a strong list of possible contenders, from New Jersey Gov. Chris Christie to Louisiana Gov. Bobby Jindal, Romney running mate Paul Ryan and former Florida Gov. Jeb Bush. As Rubio continues to expand his profile, critics will increase scrutiny.

“The wattage goes up significantly on the bulb that shines once you try to emerge on the national stage,” said Rod Smith, chairman of the Florida Democratic Party, which will happily share a dossier, hundreds of pages long, that opposition researchers assembled on Rubio as he was being considered for Romney’s running mate.

Rubio was one of Romney’s top surrogates, soaking up exposure in key states including Ohio, Colorado and Nevada. He did 60 events and so many interviews his staff lost count, more than 30 alone on the day of the first presidential debate in Denver.

Rubio, naturally, denies any plans other than serving in the Senate (his first term expires in 2016) but says he wants to be a leading figure in shaping the future of the GOP. During an Atlantic magazine forum Thursday, he said his modest background provides “insight into what our party should be more about.”

Invoking a shrinking middle class, he said Republicans “need to show how limited government and free enterprise principles can turn that around. And if we do, I think we’ll be successful. And if we don’t, I think we’ll have more days like last Tuesday.”

Immigration dilemma

Romney’s defeat brought many lessons, none more stark than the problem Republicans face with Hispanics. Obama took 71 percent of the vote, a bigger share than his 2008 victory despite a tough economy. Because Hispanics are the fastest growing group in the country and the white vote is declining, Republicans must perform better or perish.

Party leaders have turned to Rubio to address a newfound interest in immigration reform, but Rubio’s own experience tracks the gyrations the GOP has felt on the issue.