The White House may wait until after a spending bill clears Congress to announce changes in immigration policy. That’s why conservatives believe that agreeing to a long-term funding measure — one that lasts until Oct. 1 of next year — would lock into place funding for Obama’s program.

“I don’t think he will do this right after the election,” a third Senate aide said of Obama. “Because he knows we will make it an issue in the lame duck, and we have the momentum. There’s no reason to pass a long-term bill with a bunch of senators who won’t be there [after January].”

Conservatives prefer short-term funding, probably through February, so they can come back to the spending fight early next year. Then, in full control of the process, they could begin withholding funding the president would need to implement  immigration changes made without Congress.

So, for example, when an appropriations bill for an individual agency such as the Department of Homeland Security goes through Congress, lawmakers would provide no funds for an activity such as issuance of a specific number of work permits.