One of the first vows that Senate Majority Leader Mitch McConnell (R-Ky.) made after Republicans won a majority in the upper chamber was that there would be no more government shutdowns on his watch.
But the new Republican Congress now faces just that possibility, with only days remaining to pass a new funding bill for the Department of Homeland Security. A growing number of Republicans are pushing for a quick resolution, but conservatives appear insistent on a confrontation with President Obama over immigration policy.
Here are some common questions about the standoff.
Why is DHS funding running out?
Last December, in a rare moment of bipartisan agreement, Congress passed a government spending bill that runs until September. But the deal came together just after President Obama announced he would take new executive actions to shield up to 5 million immigrants from the threat of deportation.
Eager to do whatever they could to block the new plans from taking effect, Republicans demanded that funding for the Homeland Security Department, which oversees immigration agencies, only be extended through Feb. 27. Some conservatives wanted to take more aggressive action in December, but GOP leaders argued that they would be in better position to fight the president when a new Republican Senate majority was seated in the new year.
In January, the House passed a bill to provide more than $39 billion for the department's operations through Sept. 30, but with amendments that would seek to prevent the immigration policies from taking effect. Because of a Democratic filibuster, the Senate has been unable to even open debate on the plan.
Why is the GOP using the department to block Obama's plans?
One of Homeland Security's core functions is ensuring the security of U.S. international borders, processing requests for citizenship or guest worker status, and prosecuting individuals who entered the nation illegally. Cutting the agency's funding was therefore seen as a way to give Republicans leverage in a fight over Obama's new actions -- either accept limits on his desired policies, or risk losing funding for the agency as a whole.
It's a similar strategy that Republicans sought to employ in 2013 just as new healthcare marketplaces were set to launch in accordance with Obama's new healthcare law. But just as the so-called "Defund Obamacare" campaign would not have necessarily prevented the program from going forward, some of the immigration-related functions of Homeland Security are funded outside of the regular appropriation process, through application fees. So even a DHS shutdown would not prevent the administration from implementing its immigration program.
What would the GOP amendments do?
One amendment would prevent using fees collected from immigrants or other federal funds to start the deferrals announced by Obama in 2014. The president's program would benefit the parents of children born in the U.S. and other groups.
Another amendment that was more narrowly approved would essentially end the president's 2012 Deferred Action for Childhood Arrivals, which provides temporary deportation relief for hundreds of thousands of young people brought to the U.S. illegally as children.
Why are Democrats filibustering?
Democrats say they're making a principled stand against what they consider a Republican strategy of holding funding for Homeland Security hostage to GOP immigration demands. They say they're open to considering legislation addressing the president's policies, but not if it puts the nation's security at risk.
More bluntly, Democrats are protecting the president, and in some respects themselves. Most support the new actions the president announced, and want to see them proceed -- particularly since the prospects for any major immigration reform legislation appear dim.
Also, Senate Democrats are now adjusting to life in the minority and eager to remain united on most issues. By preventing the bill from even reaching the floor, they avoid having to cast votes on additional immigration-related amendments Republican senators might propose that would expose differences within the party on the issue.
What are the options now, with the Senate uanble to pass the House bill?
House Republicans refuse to even publicly consider bending on their bill, and say it's first up to McConnell to come up with a new plan that could pass there. McConnell has now done that, announcing Tuesday he was asking Democrats' help to take up the House bill with a commitment to strip out the immigration amendments. At the same time, he has introduced a separate bill that would seek to block only Obama's most recent immigration actions -- legislation that would almost certainly fail.
The new, so-called "clean" funding bill could pass the Senate with bipartisan support. House Democrats would probably also vote to pass the bill there, but House Speaker John A. Boehner (R-Ohio) would probably face heavy pressure from many of his members to even bring the bill to the floor for a vote.
Does the recent decision by a federal judge in Texas to block Obama's immigration plan affect the debate in Congress?
This is a question that even divides some conservatives. Some see the court battle as an acceptable alternative to legislation that would block the president's new policies. But many others are skeptical; they question whether the Texas injunction will survive on appeal and want their bill as a backstop.
The legal victory only reaffirmed for many lawmakers that they were on the right side of the law in this fight with the president.
But Republicans who are increasingly wary of a shutdown say the court battle is their best option at his point and are urging party leaders to seek a quick resolution. Sen. Susan Collins (R-Maine) said the judicial system was "an alternative way to deal with the president's overreach. Now that one court has ruled to put a stay in his executive order, perhaps that frees us to go forward and get the department fully funded."
Sen. John Cornyn of Texas, the No. 2 Republican in the Senate, suggested leadership was coming around to that view, posting on Twitter on Tuesday: "With a federal court injunction in place, no funds appropriated for DHS can fund POTUS's executive action on immigration. It is that simple."
What are the chances that the Homeland Security Department will shut down. What will happen then?
In a real sense, the department won't ever fully "shut down." All federal agencies are now required to put together contingency plans in the event that funding runs out in these types of standoffs. And because of the very nature of Homeland Security, a significant portion of its workforce would be deemed as "essential" and therefore required to continue working.
But those workers -- approximately 200,000 of the department's more than 230,000 employees, according to DHS' contingency plan for the 2013 shutdown -- would have to work without pay for as long as there was a lapse in funding. That includes 97% of employees in Citizenship and Immigration Services, 92% of the Secret Service, 93% of the Transportation Safety Agency, and 88% of Customs and Border Protection.
Some parts of the department that get funding from other sources -- application fees or user fees, for instance -- would be able to continue operating. If not for the Texas injunction, DHS employees could still be processing requests for deportation deferral.
But Homeland Security Secretary Jeh Johnson said Tuesday that the potential shutdown, and even another short-term funding measure, would hurt the agency.