Sen. Barbara Mikulski (D-Md.), center, shakes hands with senator-elect Joni Ernst (R-Iowa) during the Senate Women Power Workshop on Nov. 13 on Capitol Hill. (Alex Wong/Getty Images)

The vote to end debate on her child-care bill had just gone through by 96 to 1, and Sen. Barbara A. Mikulski (D-Md.) was taking a victory lap.

“I think we did a great job,” Mikulski told a handful of reporters in a Thursday news conference with the bill’s Republican co-sponsor, Sen. Richard Burr of North Carolina. “We think this is a model for the way the Senate can work together.”

It may also be a sign of how low the bar is for what constitutes “working together” in Congress these days that this particular matter was something to crow about. A minor reauthorization vote after 18 years on the books, the noncontroversial child-care block grant program was something that, in Mikulski’s words, “everyone said could not be done.”

What Mikulski succeeded in doing with this bill is what she wanted to do in two years at the helm of the powerful Senate Appropriations Committee but could not: overcome the dysfunction that makes debating and voting on bills almost impossible.

On Jan. 3, Mikulski will hand over her gavel. In December 2012, she became the panel’s first female chairman, promising a “new day” on the committee that decides the distribution of federal funds.

At the time, Mikulski was not next in line for the post; two more senior senators had declined to take it. But she was positioned to use it well. She had served on the committee since joining the Senate in 1987. A social worker turned politician, she was a forceful presence on many pieces of legislation, passionately liberal on certain issues but also committed to working closely with Republicans.

The 4-foot-11 Baltimore native who once described herself as “a little stealth rocket . . . under everybody’s radar” is now an institution, respected and a little bit feared on both sides.

“She is one of the most tenacious individuals I know in the U.S. Senate,” Burr said Thursday. “If you are going to take on something tough, she is the partner that you want.”

During her tenure, Mikulski has brought hundreds of millions of dollars in federal funds to Maryland, fueling the state’s growing defense and cybersecurity industry. Just two months ago, she helped land a $10 million grant to widen Route 175 near Fort Meade, as well as $15 million to develop cybertechnology training at state community colleges. She fought for a transportation funding formula that gave Maryland $780 million a year for highways and transit.

She and her allies say that Maryland will not suffer in her demotion from chairman to ranking Democrat, given strong relationships with her Republican counterparts.

“Clearly, it would be better for her in the majority,” said Sen. Benjamin L. Cardin (D-Md.). “I think she’s still an incredible presence. No one has ever known Senator Mikulski not to be visible.”

Rep. C.A. Dutch Ruppersberger (D-Md.), whose district is home to the National Security Agency and Fort Meade, said the amount of federal infrastructure in the state protects it from dramatic changes in funding.

“We won’t have the problems that other jurisdiction might be fighting, not when you’re dealing with national security,” he said.

Maryland lawmakers forcefully denied the notion that, after this year’s election results, Virginia has gained a toehold in the battle over where the new FBI headquarters will land. Virginians have suggested that the White House, looking toward 2016 and less inclined to show Mikulski deference, might give their state renewed consideration in a decision that rests with the Obama administration.

“I don’t think it’s about Democrats or Republicans. I think it’s about the FBI,” said Mikulski, who has pushed for the massive agency to move to Prince George’s County. Moreover, she added, “I continue to be the vice chair of the Appropriations Committee.”

Nor do any of her colleagues think she plans to retire in 2016, although she will turn 80 that year, and Republicans may well retain control. On the morning Mikulski’s bill sailed through its preliminary vote, Senate Democrats spent 31 / 2 hours lamenting the eight seats lost nationally on Nov. 4.

“I am really 100 percent certain that she is going to run for reelection,” Cardin said.

Mikulski has begun strategizing for “victory 2016,” telling fellow Democrats in an e-mail that “election results have cast upon me the role of titular leader of the MD Democratic Party.”

It was election-year politics, Mikulski and other Democrats say, that derailed her chief goal as appropriations chair. Mikulski tried to do something more ambitious and less rewarding than bringing home bacon during her tenure leading the money committee.

She wanted to return to “regular order,” which means that the 12 appropriations bills that typically pass through the committee would be debated, amended and voted on one by one before they move on to the full chamber. Instead, in recent years, those bills get stalled, and the government is funded through omnibus packages or continuing resolutions that restrict the normal process of debate — and the opportunity to consider amendments.

While Mikulski worked closely with House Appropriations Chairman Harold Rogers (R-Ky.) on a bipartisan compromise, Senate Majority Leader Harry M. Reid (D-Nev.) and Minority Leader Mitch McConnell (Ky.) hit an impasse sparked by the Republican leader’s desire to push an amendment blocking new carbon emission rules. Debates that were supposed to happen in June and July never did, with Reid worried that Republicans would simply use them to embarrass Democrats before the midterms.

Even now, Mikulski insists the effort won’t end until the new Congress begins.

“Between now and January 3rd, I chair the full committee. I’m working in a fast way, deliberate, determinative,” she said in a brief interview. “We will come as close to filing the regular order as we can.”

Some Republicans are talking about using the budget to block President Obama from taking unilateral action to protect from deportation millions of illegal immigrants in the United States. Asked about that issue Thursday, Mikulski said she had heard only “rumors.”

“Any other questions on the child-care bill and actually where there has been truly a successful effort of bipartisanship?” she asked. No one responded.

An hour after the child-care vote, Mikulski stepped into another role that she will not lose when Republicans take over — “dean” of the Senate women. In 2011 she became the longest-serving woman in the chamber. Along with Sen. Susan M. Collins (Maine), the senior Republican woman, she gathered about a dozen of the chamber’s female lawmakers.

“We want to welcome you,” she said to the women elected this month, Republicans Shelley Moore Capito of West Virginia and Joni Ernst of Iowa.

“We are not a caucus, because we have different views,” Mikulski told them. “But we are a force in how to get things done.”