The Senate just voted 33-63 not to invoke cloture on the immigration bill, meaning that it cannot proceed to a final vote at this time. However, Senate Majority Leader Harry Reid (D.-Nev.) is planning to spend the afternoon twisting arms in anticipation for another cloture vote at 5 p.m. today.

In the meantime, Capitol Hill sources tell me that the White House may be working with Senate supporters of the original bill to strip out all amendments that have been added. Such a move deeply worries conservatives.

“It looks like the ‘Masters of the Universe’ might want a mulligan,” said one conservative GOP aide. “But there are some folks who take their golf pretty seriously here in the Senate. I expect multiple senators would object to such a desperate tactic.”

Conservative activists have ramped up calls to key Senate offices today in hopes that enough grassroots pressure will convince senators to oppose the bill.