Leading Democratic and Republican senators pledged to propel far-reaching immigration legislation through the Senate by summer providing a possible path to citizenship for an estimated 11 million people now in the U.S. illegally.

The momentum for an immigration overhaul should get a further boost Tuesday when President Barack Obama travels to Las Vegas to lay out his proposals for immigration changes that are expected to be similar to the senators' proposals in many ways.

Administration officials said Obama would largely endorse the senators' efforts, though immigration advocates said they expected the president's own proposals to be more progressive than the Senate group, including a faster pathway to citizenship.

The senators on Monday acknowledged pitfalls that have doomed such efforts in the past, but they suggested that November's elections _ with Hispanics voting heavily for Obama and other Democrats _ could make this time different. Several prominent Republicans are arguing their party must get on board with immigration overhaul if they hope to make inroads with Hispanics, a burgeoning and increasingly crucial voting group.

Still, passage of the emotionally charged legislation by the Democratic-controlled Senate is far from assured, and a taller hurdle could come later in the House of Representatives, which is dominated by conservative Republicans who have shown little interest in immigration overhaul.

Besides the citizenship provision, the measure would increase border security, allow more temporary workers to stay and crack down on employers who would hire illegal immigrants. The plans are still short on detail, and all the senators conceded that months of tedious and politically treacherous negotiations lie ahead.

But with a re-elected Obama pledging his commitment, the lawmakers argued that six years after the last sustained congressional effort at an immigration overhaul came up short in the Senate, chances for approval this year are much better.

“Other bipartisan groups of senators have stood in the same spot before, trumpeting similar proposals,” said Sen. Charles Schumer, a New York Democrat. “But we believe this will be the year Congress finally gets it done. The politics on this issue have been turned upside down,” Schumer said, arguing that polls show more support than ever for immigration changes and political risk in opposing it.

“Elections. Elections,” said Sen. John McCain, the former Republican presidential candidate who lost to Obama in 2008. “The Republican Party is losing the support of our Hispanic citizens. And we realize that there are many issues on which we think we are in agreement with our Hispanic citizens, but this is a pre-eminent issue with those citizens.”

Obama got 71 percent of the Latino vote in November compared to 27 percent for Republican Mitt Romney.

It's one of the few issues that may bring Democrats and Republicans together in highly divided times. The Obama administration faces major Republican resistance to his other major goals, from gun control to protecting America's social safety net as Washington debates how to trim the U.S. deficit.

In a five-page framework, the lawmakers set out plans for creating a path to citizenship for illegal immigrants already here, contingent upon securing the border and better tracking of people in the U.S. on visas, overhauling the legal immigration system, including awarding permanent residency to immigrants who obtain certain advanced degrees from American universities, creating an effective high-tech employment verification system to ensure that employers do not hire illegal immigrants in the future and allowing more low-skill and agricultural workers.

Among the senators endorsing the new principles is a notable newcomer: Florida Sen. Marco Rubio, a potential 2016 presidential candidate whose conservative bona fides may help smooth the way for support among conservatives wary of anything that smacks of amnesty. Rubio has been working with the group while also detailing his own similar immigration proposals to selected media, getting a generally positive reaction from conservative media.

“There are 11 million human beings in this country today that are undocumented. That's not something that anyone is happy about; that's not something that anyone wanted to see happen, but that is what happened. And we have an obligation and the need to address the reality of the situation that we face,” Rubio said Monday.

A year after U.S. Border Patrol apprehensions of illegal border crossers plunged to the lowest levels in nearly 40 years agents have seen a slight increase in arrests, according to Border Patrol arrest data obtained by The Associated Press. In the budget year that ended in September, Border Patrol agents arrested 356,873 would-be border crossers along the Mexican border. In fiscal year 2011, agents along the Mexican border made 327,577 arrests.

In order to satisfy the concerns of Rubio and other Republicans, the senators are calling for the completion of steps on border security and oversight of those here on visas before taking major steps forward on the path to citizenship.

Even then, those here illegally would have to pass background checks and pay fines and taxes in order to qualify for a “probationary legal status” that would allow them to live and work here _ and not qualify for federal benefits _ before being able to apply for permanent residency, a critical step toward citizenship. (AP)