In a letter sent one week before Christmas, Sen. Bob Casey (D-Pa.) called on Senate leaders to move quickly in the new session on an economic stimulus package that could stuff $850 billion in the stockings of small businesses and families.

Laying the groundwork for next year, Casey’s letter to Senate Majority Leader Harry Reid (D-Nev.) and Minority Leader Mitch McConnell (R-Ky.) warned that “the severity and length of this recession requires us to take significant action.”

“We’ve got to get this done. We’ve got to jump-start the economy, because it’s in a ditch,” Casey told reporters on Thursday. “The worst thing we could do would be to wait another month, or two or three, to fare it out and make it look nicer.”

Casey set an ambitious deadline for Congress to pass an economic stimulus package that would be ready for President-elect Barack Obama’s signature on Jan. 20, when he is sworn into office. That means Congress would have just two weeks to put together a comprehensive stimulus package.

Such an expensive price tag “might limit [our] horizons” for other legislative priorities, Casey noted, but he did not flinch about the price tag or the timeline.

Casey listed off a kitchen sink’s worth of priorities for the stimulus bill, including money for transportation and water projects and increased funding for the Community Development Block Grant program. He called for a financial boost for unemployment insurance and food stamps, and micro-loans for small business.

Casey dismissed concerns that such a fast-moving bill could be a funding vehicle for pet projects and earmarks, and he expected bipartisan support for legislation.

“I would obviously prefer a broad bipartisan consensus, but we need to get this done,” he said, noting that Obama’s pledge for bipartisanship might help the bill along. Obama “doesn’t just talk the talk, he walks the walk.”