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UNDATED (CBS) -- The battle over immigration reform takes center stage on Capitol Hill today. A bipartisan group of senators has reached a deal to introduce immigration reform today.

Congress will once again take up immigration reform but this time there's bipartisan support to get a deal done. Sen. John McCain says, "I'm confident, guardedly optimistic, that this time we can get it done."

The deal includes tougher border enforcement to appease republicans. And for Democrats, it's a pathway to citizenship for the estimated 11 million illegal immigrants now living in the United States. Sen. Bob Menendez says, "First of all, Americans support it, in poll after poll. Second, Latinos expect it. Thirdly, Democrats want it. And fourthly, Republicans need it."

There's one senator among this bipartisan working group who is seen as critical to getting this deal through both chambers. Sen. Bob Corker says, "I do like the things that Marco Rubio has been laying out."

Florida Senator Marco Rubio is a tea party favorite and a potential presidential candidate in 2016. Many here say he's key to getting conservatives to support the bill. Rep. Paul Ryan says, "I support and agree with the principals that he laid out about earned legalization. Making sure you're not rewarding people who cut in line, but making sure that we can fix this problem."

And then there's the political calculus. Some Republicans say they need this bill to win over Hispanic voters. McCain says, "Look at the last election. We are losing, dramatically, the Hispanic vote, which we think should be ours for a variety of reasons, and we've got to understand that."

Hispanics supported President Obama over Mitt Romney with more than 70-percent of the vote. President Obama will address immigration reform tomorrow at a speech in Nevada.