as c ,Ncur I lark alms January 30. 2013 On Immigration, Obama Assumes Upper Hand By MICHAEL D. SHEAR and MARK LANDLER WASHINGTON — As the specifics of immigration legislation take shape on Capitol Hill, President Obama is making it clear that he wants the overhaul on his terms. Officials in the West Wing are convinced that the politics of the immigration issue have firmly shifted in their direction. That belief is fueling the president's push for quick action and broad changes that go beyond what Republicans are signaling would be acceptable if they are to back legislation that allows a path to citizenship for millions of illegal immigrants. The administration's confidence — which was communicated to immigration advocates in a series of conference calls and meetings last week — is rooted in the sense among the president's political advisers that Republicans are eager to embrace broad immigration changes as a way of improving their electoral appeal among Hispanic voters. "We're giving them some space," said Dan Pfeiffer, a senior adviser to the president. But in the meantime, he said, "we're going to continue to make the case to the country about why immigration reform should be done and to put pressure on Republicans that they need to do it." While aides say Mr. Obama is open to some negotiation over the contours of the immigration changes he laid out Tuesday in Las Vegas, senior administration officials are convinced that there is little risk in pushing hard for Mr. Obama's immigration priorities, betting that Republicans will think twice about voting down a bill championed by a president who is highly popular among the very voters they covet. The principles Mr. Obama embraced this week differ in some central ways from the effort under way in the Senate, where Marco Rubio, Republican of Florida, and Senator Charles E. Schumer, Democrat of New York, and six other senators are working toward a bill that could be debated and voted on as early