Washington ? President Bush is putting his influence within his own party to the test today as he pleads personally with skeptical Senate Republicans to resurrect his immigration bill.

Despite his confident tone Monday about the measure’s fate, Bush is facing a hostile audience that has shown little appetite for following his lead on the contentious issue.

Bush left no room for the possibility that his bid to legalize up to 12 million unlawful immigrants while tightening border security – among his top domestic priorities – might die. “I’ll see you at the bill signing,” he said while traveling in Bulgaria before flying home.

Still, weakened by his sagging poll numbers and a sense within GOP ranks that the president has lost touch with his core supporters on immigration, Bush may well lack the clout he would need to persuade Republicans to back the measure, say lawmakers and strategists.

Republicans overwhelmingly favor enforcing current laws over giving unlawful immigrants a path to citizenship, putting Bush on the wrong side of an issue that unites the party, said GOP pollster Tony Fabrizio.

Bush’s campaign for the broad immigration measure “is certainly not helpful, particularly with the base,” Fabrizio said. “This issue right now is the most glaring one where there is almost unanimity on the other side of (Bush’s) position.”

The president, who helped shape the bipartisan immigration compromise that collapsed in the Senate last week, will huddle with Republicans over lunch today, aiming to persuade them to give the measure another chance.