Sen. John McCain (R., Ariz.) vowed that the overhaul would not repeat "the mistakes of 1986," when, he said, an amnesty program legalized millions of illegal immigrants, but created conditions for the illegal entry of many millions more.
The other members of the group behind the proposal are Democrats Richard J. Durbin of Illinois, Robert Menendez of New Jersey, and Michael Bennet of Colorado, along with Republicans Lindsey Graham of South Carolina, Marco Rubio of Florida, and Jeff Flake of Arizona.
The White House embraced the immigration-reform proposal Monday, but stopped short of pledging President Obama's signature, noting that the legislation has yet to be drafted.
"It's a set of principles that mirror the president's principles," White House press secretary Jay Carney told reporters at Monday's briefing. Obama is expected to present his own proposal Tuesday at an event in Las Vegas.
Menendez, along with other congressional Hispanics, met with Obama on Friday and said the president pledged that immigration reform would be a top priority.
"I am the most optimistic I have been in quite some time" that reform is within reach, Menendez said at the afternoon news conference carried live on cable news networks.
Menendez, born in America but the son of Cuban immigrants, cast the issue in economic terms.
"If you got up this morning and had fruits for breakfast, it was probably picked by the bent back of an immigrant worker. If you in fact had . . . chicken for lunch, you probably had it [plucked] by the cut-up hands of an immigrant worker," Menendez said.
He added that immigrants also contribute to developing "cutting-edge technology." Part of the immigration plans calls for giving green cards to immigrants who have received doctorates or master's degrees at American universities.
"In so many dimensions," said Menendez, "this is about the economy of our nation as well."
Menendez, one of only three Hispanics in the Senate, has worked on immigration plans for years, but the issue has been intractable. He said in November that the presidential election, in which Hispanics overwhelmingly voted for Obama, amounted to a "mandate" for immigration reform. He has since been one of eight senators, four from each party, to work on the issue.
At the news conference, Menendez gave an opening statement in English, then switched to Spanish. Rubio, whose parents were also from Cuba, was next up to the podium. He turned to McCain and said: "John, I don't agree with any of the stuff he just said about you in Spanish."
The senators' announcement comes as a bipartisan group of House members is also working on an immigration proposal. House Speaker John A. Boehner (R., Ohio) said last week that they "basically have an agreement."
Boehner - who has said that Congress must deal with immigration this year - said he welcomed the Senate proposal and looked forward to reviewing it.
The Senate group outlined the key balance in its proposed framework: Legalization would be afforded almost immediately to the nation's 11 million undocumented immigrants, provided they pay back taxes and a fine. But the opportunity to pursue full citizenship would not become available until the border was secured and new systems were in place for employers to verify workers' immigration status and for the government to ensure that legal immigrants cannot overstay their visas.
The document also calls for tying flows of legal immigration to the nation's unemployment rate, but generally expanding visa programs to discourage people from crossing the border without permission.
"It's a pretty straightforward principle," said Rubio, who switched between English and Spanish during the lengthy rollout. "It's a principle that says we have to modernize our legal immigration system, we have to have a real enforcement mechanism to ensure we're never here again in the future, and we have to deal with the people that are here now in a way that's responsible but humane."
Despite being written by lawmakers of both parties, the proposal could face sharp opposition on Capitol Hill, where the last attempt at an immigration overhaul sank in 2007.
Three years later, in the 2010 lame-duck session, legislation that would have provided a path to citizenship for young people who were brought to the country illegally as children fell short of passage in the Senate.
Senate Immigration Plan
Here are some details of the bipartisan Senate framework on immigration reform.
Creating a path to citizenship for 11 million illegal immigrants already in the country
First, increase border security efforts including adding unmanned drones, surveillance equipment, and more border agents.
Require completion of an entry-exit system to track whether people in the U.S. on temporary visas have left as required.
Create a commission of lawmakers and community leaders living along the southwest border to make a recommendation about when the border security measures have been completed.
While security measures are under way, illegal immigrants can register with the government, pass background checks and pay fines and back taxes in order to earn "probationary legal status."
Once security measures are in place, immigrants on "probationary legal status" could apply for permanent legal status behind other immigrants already in the system.
People brought to the U.S. as children, and farmworkers, would have a quicker path to citizenship.
Improving the legal immigration system
Reduce backlogs in family and employment visas.
Award green cards to immigrants who obtain advanced degrees in science, technology, engineering or math from American universities.
Admitting new workers
Employers could hire immigrants if they can demonstrate they were unsuccessful in recruiting an American and the hiring of an immigrant will not displace American workers.
Create an agricultural worker program to meet the needs of the nation's agriculture industry when American workers are not available.
Allow more lower-skilled immigrants to come to the country when the economy is creating jobs, and fewer when it is not.
Permit workers who have succeeded in the workplace and contributed to their communities over years to earn green cards.
- Associated Press
Staff writer Jonathan Tamari contributed to this article.