Congress returned for a final two-week sprint Monday with much to do — including a Dec. 11 deadline to continue funding the government — and little consensus over how to do it.
Republicans have not yet ascended to majority control of Congress after their election sweep; that happens in January. But in many ways it doesn't matter.
The lame-duck days ahead will provide an early test of whether House Speaker John A. Boehner and Senate GOP leader Mitch McConnell can control their often rebellious Republican ranks — particularly over the immigration issue.
Many Republicans want to use all means available to stop President Obama's executive action on immigration, viewing their electoral victories as a mandate against the White House approach.
But a prolonged debate over an issue in which Republicans lack their own alternative could drag on indefinitely — and that is not the way party leaders hoped to start the new year.
Here are a few items to watch in the final stretch of the 113th Congress, which could set the tone for the 114th.
Avoiding another government shutdown
After last year's politically damaging government shutdown, it's tough to imagine lawmakers entertaining a repeat.
But a core group of conservatives are so opposed to Obama's decision to halt deportations for nearly 5 million immigrants that they are threatening Boehner's and McConnell's hold on the party.
"The Republican establishment won't fight the president's amnesty unless conservatives force them to," wrote Senate Conservatives Fund, a group that helps elect conservative lawmakers.
Led by McConnell, GOP leaders have floated a proposal that would allow Congress to fund most of the government through the end of the fiscal year in September but would fund immigration agencies only until January.
That would avert a shutdown this month and allow the new Congress to revisit the issue once the GOP majority convenes.
But conservatives aren't buying the offer. They view it as "the old Lucy and the football trick," as Senate Conservatives Fund wrote, an endless promise for a fight on immigration that will never come.
Leaders are scrambling for a Plan B. Funding for the government expires at midnight Dec. 11.
War powers and the battle against Islamic State
Congress also needs to approve must-pass Defense Department legislation, a sweeping annual bill that sets pay for the troops and other Pentagon policy.
But the legislation has become the prime venue for a broader foreign policy debate over the administration's military campaign against Islamic State militants in Iraq and Syria.
Many lawmakers want Congress to decide whether the president has authority under the War Powers Act to conduct the military operation. Sen. Rand Paul (R-Ky.) is among those leading efforts to require a vote.
Issues of war and peace create an unusual alliance of libertarian Republicans and liberal Democrats who tend to oppose military intervention, making the outcome of any war-powers vote — and the future of the Pentagon's policy — highly uncertain.
The debate unfolds as the Senate will soon be asked to confirm a new Defense secretary to replace Chuck Hagel, who is resigning.
A year-end fight over war powers is not what leaders of either party had in mind for this lame-duck session. If the conversation begins, there is scant hope the issue could be resolved quickly.
Congress always seems to work best when facing a deadline, and this year is no different as lawmakers tackle a list of must-pass items.
Legislation to temporarily extend niche industry tax breaks, which are routinely approved in lame-duck sessions, and to allow tax-free shopping on the Internet remain in the balance.
Lawmakers continue working on last-minute compromises to create more comprehensive solutions to these patchwork policies. But as the days pass, resolution is more than likely to slip out of reach. Expect another round of stopgap measures that punt the tougher resolutions to the new year.