“He’s trying to have it both ways,” said Mark Krikorian, executive director of the Center for Immigration Studies, which calls for tighter enforcement before broader steps are taken. “It’s not going to be fatal to support legalizing illegal immigrants who came here when they were very young. But any bill that has a broader amnesty in it would end his presidential prospects.”

Diaz-Balart, by contrast, faces little political risk.

His district in Miami is exceedingly safe — he just won a sixth term with 76 percent of the vote — and many of his constituents are Hispanic. He was one of the few Republicans to vote for the Dream Act, which would have created a pathway to citizenship for young immigrants.

Rubio opposes the Dream Act but used it as the basis for a proposal to grant legal status to some immigrant youths. The idea came under attack from some conservatives, and Rubio has yet to release details. He said he would release his plan early next year, though the election has emboldened young activists and Democrats to push for the full Dream Act.

Obama, who failed to deliver on promised reforms during his first term, told activists Tuesday that it would be his top priority after the inauguration. But getting what he wants will require help from Republicans.

A broad deal would continue a legacy for the Diaz-Balart family. His older brother, retired Rep. Lincoln Diaz-Balart, turned back changes that denied disability benefits and food stamps to legal immigrants, and in 1997 was the driving force behind the Nicaraguan Adjustment and Central American Relief Act, which granted legal residency to hundreds of thousands of immigrants in the United States.

“I’m not naive,” Mario Diaz-Balart said. “This is a very difficult, controversial and emotional issue. It has been used by both parties as an election tool. But it’s pretty obvious it hasn’t worked well for Republicans.”

With renewed interest among the GOP, Diaz-Balart has emerged as a leader in the House, working quietly with two California Democrats, Reps. Zoe Lofgren and Xavier Becerra, to forge legislation. A similar group of eight senators has begun talks.

Conspicuously absent: Rubio, who has devoted more of his public time recently to pitching himself as an advocate for the middle class. He did not mention immigration in a high-profile speech he delivered in Washington earlier this month. Some of his advisers want him to avoid being labeled a Hispanic politician with a singular focus.

“We still haven’t made any firm decisions about which process we’re going to plug into to get engaged,” Rubio said. “But we’re going to have some specific ideas about immigration soon.”

Diaz-Balart says any approach has to include a way to deal with the 11 million undocumented residents. Immigrant advocates want a pathway to citizenship, but many conservatives view that as amnesty, even if immigrants must pay a fine, have no criminal record and demonstrate command of English.

Diaz-Balart, 51, rejected an alternative to create legal status for undocumented residents so they could live without fear of deportation and gain other rights (but not the right to vote) while pursuing citizenship through regular channels. That is essentially a bigger version of what Rubio wants with his Dream Act alternative.