White House, senators starting push on immigration

A few other lawmakers have also been involved, including Democrat Michael Bennet of Colorado and Republicans Jeff Flake of Arizona and Mike Lee of Utah. It's not clear whether all those involved will sign on to the principles the group hopes to roll out next week.

Details of the Senate proposals remain unclear, but the principles are expected to address a process toward legalizing the status of unauthorized immigrants already in the country; border security; verification measures for employers hiring workers and ways for more temporary workers to be admitted into the country.

On the path to citizenship, Schumer and Graham have in the past supported requiring illegal immigrants to admit they broke the law, perform community service, pay fines and back taxes, pass background checks and learn English before going to the back of the line of immigrants already in the system.

Several of the senators negotiating the immigration principles are veterans of the comprehensive immigration reform effort under then-President George W. Bush. That process collapsed in 2007 when it came up well-short of the needed votes in the Senate, a bitter outcome for Bush and the late Sen. Edward M. Kennedy, the Democrats' leader on the legislation.

Some Republicans still lament that result as a missed opportunity for the party that could have set the GOP on a different path to reach more Latino voters.

Rubio is a relative newcomer to Senate negotiations on the issue, but he's seen as a rising star in his party and a potential 2016 presidential candidate. As a charismatic young Hispanic leader, his proposals on immigration have attracted wide notice in recent weeks. And as a conservative favorite, unlike McCain or Graham, his stamp of approval could be critical to drawing in other conservative lawmakers.

A Republican aide said that Rubio has made clear in his interactions with the group that he couldn't sign on to proposals that deviated from the principles he himself has been laying out in recent media interviews, including border security first, a guest-worker program, more visas for high-tech workers and enforcement in the workplace. As for the illegal immigrants already in the country, Rubio would have them pay a fine and back taxes, show they have not committed crimes, prove they've been in the country for some time and speak some English and apply for permanent residency. Ultimately, citizenship, too, could be in reach, but only after a process that doesn't nudge aside immigrants already in line, and Rubio hasn't provided details on how long it all might take.

The aide was not authorized to discuss private deliberations and requested anonymity in order to describe them.

An open question for the Senate group has been whether Obama would release an actual bill or just his own principles. Republicans in the group tend to believe that a bill handed down by the White House could seriously complicate the process, spooking the GOP by coming off as a purely political move, since a White House-written bill would have little chance of actually passing.

The White House and Senate Democrats favor addressing immigration through one broad package of legislation, while some Republicans lawmakers prefer to tackle the issue through several separate bills.