WASHINGTON (AP) -- President Barack Obama's second-term agenda will be robustly tested this week, with gun control and immigration in the spotlight on Capitol Hill and the White House releasing his long-delayed budget blueprint. In a taste of what lies ahead, Democratic gun legislation arrived on the Senate floor Monday — facing an aggressive Republican effort to block it.
In an era of deep partisanship and divided government, Obama knows he won't get everything he wants on the three big issues as he seeks to capitalize on the national support that brought him re-election. But the scope of his victories or defeats on these issues will in part define his legacy and determine how much political capital he retains for his final four years in office.
"This is his best chance to set up the next 3½ years where he's the pace car," said Sara Taylor Fagen, who served as political director for President George W. Bush.
But much of what happens during this pivotal period is out of the president's direct control. Members of Congress will largely determine whether his proposals to deal with gun ownership, revamp broken immigration laws and reduce the federal budget deficit gain traction.
Lawmakers, back in Washington after a two-week recess, are expected to take significant steps on some of the issues this week. A bipartisan group of senators could unveil highly anticipated immigration legislation by the end of the week. And Democrats brought a gun-control bill to the Senate floor Monday afternoon amid a threat from conservative Republicans to use delaying tactics to prevent formal debate from even beginning.
Obama himself flew to Connecticut for a new gun-control speech, and he was bringing relatives of Newtown shooting victims back to Washington on Air Force One to lobby members of Congress.
"The day Newtown happened was the toughest day of my presidency," Obama said Monday. "But I've got to tell you, if we don't respond to this, that'll be a tough day for me, too. Because we've got to expect more from ourselves. We've got to expect more from Congress."
In the midst of all that, Obama will release his 2014 budget, which already is drawing opposition from both parties ahead of its Wednesday publication. Republicans oppose Obama's calls for new tax hikes, and many of the president's fellow Democrats balk at his proposals for smaller annual increases in Social Security and other federal benefit programs.
The White House tried to play down the significance of the week's overlapping events to the president's broader objectives, with Obama spokesman Jay Carney saying the administration is always trying to move forward on "the business of the American people."
Said Carney: "Every one of these weeks is full of the possibility for progress on a range of fronts."
But Obama's advisers know the window for broad legislative victories is narrower for a second-term president. Political posturing is already underway for the 2014 midterm elections, which will consume Congress next year. And once those votes for a new Congress are cast, Washington's attention turns to the race to succeed Obama.
Patrick Griffin, who served as White House legislative director under President Bill Clinton, said Obama's legislative efforts this year are likely to be the "sum and substance" of his second-term agenda.
"I think it would be very tough to put another item on the agenda on his own terms," said Griffin, adding that unexpected events could force other issues to the fore.
On both ends of Pennsylvania Avenue, the outcome of the debate over gun measures is perhaps the most uncertain. The White House and Congress had little appetite for tackling the emotional issue during Obama's first term, but December's horrific elementary school massacre in Connecticut thrust gun control to the forefront of the president's second-term agenda.
If a bill does reach Obama's desk this year, it will be far weaker than what he first proposed. An assault weapons ban appears all but dead, and a prohibition on ammunition magazines carrying over 10 rounds, also supported by the president, seems unlikely to survive.
The White House is largely pinning its hopes on a significant expansion of background checks for gun buyers, but the prospects for such a measure are far from certain, despite widespread public support. The best chance at a deal appears to rest on eleventh-hour talks between Republican Sen. Pat Toomey of Pennsylvania and conservative Democratic Sen. Joe Manchin of West Virginia.
The White House is far more confident about the prospects for a sweeping immigration deal that could provide a pathway to citizenship for millions of people who now are in the country, tighten border security and crack down on businesses that employ people illegally. But the president is treading carefully on the sensitive issues, wary of disrupting a bipartisan Senate working group that has been laboriously crafting a bill.
The group of four Republicans and four Democrats could unveil that legislation as early as this week, a pivotal development that would open months of debate. While the growing political power of Hispanics may have softened the ground for passage, significant hurdles remain.
Looming over Obama's entire domestic agenda is the economy, including the deficit deal that has long eluded him. The budget Obama will release Wednesday proposes spending cuts and revenue increases that would project $1.8 trillion in deficit reductions over 10 years.
That would replace $1.2 trillion in automatic spending cuts that are poised to take effect over the next 10 years if Congress and the president don't come up with an alternative.
Seeking to soften bipartisan opposition to his budget proposals, Obama will dine Wednesday night with a dozen Republican senators, part of the broader charm offensive he launched in recent weeks.
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