WASHINGTON — Republican lawmakers, facing the impending end of one-party control of Congress in January, will try again to fund President Trump’s wall on the southern border, risking a possible, partial government shutdown in the face of newly empowered Democratic opposition in the House.
For their part, Democrats, buoyed by their midterm success, hope to attach legislation that would protect the special counsel, Robert S. Mueller III, to one of seven remaining appropriations bills. The bills, which have a Dec. 7 deadline, would fund a number of federal agencies, including the Homeland Security, Agriculture and Commerce Departments.
Lawmakers and aides in both chambers say they do not want to pass a stopgap spending bill to keep the government open into the new Congress. But Mr. Trump’s lingering threat to veto any bill that does not have billions of dollars in funding for the border wall has raised the possibility of a partial government shutdown next month.
With a House majority coming, Democrats have little incentive to give the president what he wants unless Republicans are willing to offer significant concessions.
The president, who met with Republican leaders Thursday afternoon in part to discuss the appropriations bills and border security, raised the specter of forcing a shutdown again in an interview with The Daily Caller on Wednesday.
“I’ll have to see how it plays out,” Mr. Trump said. “But I may very well be willing to shut down the government.”
Mr. Trump has leveled such threats before only to acquiesce to lawmakers and keep the government open. (The president has also retreated from his vow during the 2016 campaign that Mexico would pay for the wall.)
A funding lapse after Dec. 7 would, among other things, shutter some national parks and the Bureau of Economic Analysis, and disrupt the Commerce Department as it struggles to assemble the already contested 2020 census.
Aides familiar with the negotiation process said lawmakers might group the seven spending bills into one package, effectively tying the wall provision to other government efforts more popular with Democrats. Democrats insist that while they are willing to fund some measures to increase border security, billions of dollars for a concrete border wall is a nonstarter.
“The Democrats and Republicans came to the $1.6 billion agreement,” Senator Chuck Schumer of New York, the newly re-elected Democratic minority leader, told reporters on Wednesday. “It is tough security. It is sensors. It is drones. It is roads. It is help at the border in a far more effective way than the wall.”
“We believe Democrats and Republicans should stick with their agreement and not let President Trump interfere,” he added. “Every time he interferes, it gets bollixed up.”
The House has allocated $5 billion for border security and wall funding. The Senate has not gone along. With new lawmakers descending on Washington and wrangling intensifying ahead of Democratic leadership elections, multiple aides said it was unlikely a compromise could emerge before the Thanksgiving break.
Republicans — including some scorned by the president for failing to “embrace” him in their failed re-election bids — are also divided over funding levels and other matters. Representative Carlos Curbelo, a defeated Republican from South Florida, still held out hope for legislation to protect young immigrants brought illegally to the country as children from deportation.
“If the president is going to try to get significant funding for border security — 10 billion, 20 billion, 25 billion — then I would only support that with a permanent solution for ‘Dreamers,’” he said, referring to those 700,000 immigrants. “They know what it would take to get my vote.”
But more hard-line members, including Representative Mark Meadows of North Carolina, the chairman of the House Freedom Caucus, have indicated that they intend to lobby for funding for the wall.
“We need to have a real conservative approach to fulfilling that campaign promise and making sure that our national security interests at the border are covered,” Mr. Meadows told reporters as he left Republican leadership elections on Wednesday.
Representative Kevin McCarthy of California, who will succeed Speaker Paul D. Ryan of Wisconsin as the top House Republican, introduced legislation this year that would provide $25 billion in funding.
Beyond his demands for a wall, Mr. Trump’s renewed attacks on the special counsel and his investigation have exacerbated another sticking point in the negotiations to keep the government fully funded.
His decision to oust Jeff Sessions as attorney general and temporarily replace him with a known critic of the investigation, coupled with a series of false accusations against Mr. Mueller’s team Thursday morning, have prompted some Democrats to press to attach a protection bill to the spending measures.
Senator Mitch McConnell of Kentucky, the majority leader, has dismissed concerns that the investigation into Russian interference in the 2016 election could be corrupted. But Senator Jeff Flake of Arizona, a Republican member of the Judiciary Committee, said Wednesday that he would withhold support for any judicial nominations that Mr. McConnell is shepherding through until such a measure is approved.
Mr. Schumer threw his support on Thursday behind Mr. Flake and Senator Chris Coons, Democrat of Delaware, who unsuccessfully tried to call for a floor vote on the Special Counsel Independence and Integrity Act.
“There is too much at stake for us to sit around and wait until the president crosses a line, creating a constitutional crisis we all abhor,” Mr. Schumer said on Thursday.
Senator Patrick J. Leahy, Democrat of Vermont, said earlier this week that Democrats are also advocating for disaster relief funding for the devastating wildfires in California and possibly post-hurricane recovery efforts in other areas to be attached to the spending bill.
Legislators are also eager to resolve an impasse over a major farm bill and the House’s decision to add new work requirements for able-bodied adults seeking food stamps, a move Mr. Trump has encouraged. The Senate passed its own bipartisan farm bill without the requirements.
In the House, both Representative K. Michael Conaway, a Texas Republican who is chairman of the Agriculture Committee, and Representative Collin C. Peterson of Minnesota, the committee’s top Democrat, have said they have no desire to scrap the negotiations over the farm bill and start anew.
“I envision us getting this on the president’s desk,” Mr. Conaway said. “There’s no reason not to.”