WASHINGTON >> Seven months into Sen. Barbara A. Mikulski’s new assignment as chairwoman of the Senate Appropriations Committee, there is already a saying among members: “We loved Byrd, we respected Inouye, we fear Barbara.”

It is not hard to see why. Mikulski, D-Md., intimidates people in a way that the two most recent committee chairmen, the late Sens. Robert C. Byrd of West Virginia and Daniel K. Inouye of Hawaii, did not. iceDuring a March floor debate, Mikulski ordered Sen. John McCain of Arizona to go back to his off and read a bill so he could properly vote on it — and McCain, chastened but cheerful, agreed.

"I will now try to carry out my mission as assigned by the distinguished chairwoman," he said.

Mikulski, who legislates with two parts accommodation and one part coercion, finds herself at the center of a spending brawl on Capitol Hill. At 77, she is the longest serving woman in Congress, the first female leader of its most august committee and the fulcrum in a fiscal fight that will dominate Washington this fall.

With the pugnacious Mikulski at the helm, the Senate Appropriations Committee — for decades a quiet outpost of bipartisan check-writing financing every corner of the government — is charged with heading off what could be the first shutdown of Washington after three years of near misses. Mikulski has begun by reviving the committee from an earlier somnolence, when staff members directed much of the action and partisan peace was kept by awarding senators money for the pet spending projects universally denounced as earmarks.

"You take your persona from the generation you come in with," Mikulski said in an interview. "And mine is a very activist generation."

The question is whether she can forge an agreement among the Senate, House Republicans and the White House, particularly when she is hobbled by an earmark ban, an austerity movement in Congress and severe discord between the House and Senate over how much money there is to spend in the first place.

Mikulski’s colleagues say she is at heart a pragmatist, but if she and her House Appropriations Committee counterpart, Rep. Harold Rogers, R-Ky., cannot find a spending level that both chambers agree to by Oct. 1, the government will run out of money — and Washington will find itself mired in the latest of budget impasses that have sent the reputation of Congress to historic lows.

"She is tough, she is determined, she is prepared," Rogers said. "She is also accommodating. But once she gets to a place, she is a bulldozer you can’t move."

Mikulski was fuming last week after Senate Republicans filibustered a housing and transportation appropriations bill, leaving the spending fight very much unresolved even as lawmakers raced for the exits and the airports for their five-week summer recess.

"Are we back to gridlock?" the obviously angry chairwoman asked, saying the bill’s failure meant public safety threats and fewer jobs.

Unlike her most recent predecessors, Inouye and Byrd, Mikulski is more than happy to raise her legislative voice. She relentlessly lobbies Sen. Harry Reid, the majority leader, to put her bills on the floor, a luxury of attention many appropriations bills have not had in years. "I would guess if Sen. Mikulski goes to see the majority leader about her bills," Sen. Lamar Alexander, R-Tenn., said, laughing, "my guess is he drops what he is doing to listen."

Mikulski does not so much walk into places as plow through them, a 4-foot-11 fireplug swathed in brightly colored blazers, often a tad out of breath. She straddles an amusing line between a jocular informality and institutional fealty.

When one reporter called out "Madame Chairwoman" behind her as he attempted to keep up in a hallway, she cracked, without stopping, "That’s right, ‘Madame Chairwoman.’ I like it."

She also waited expectantly for an aide to pull out her chair so she could sit down to preside over a recent committee meeting.

Last month Mikulski went so far as to halt another hearing to respond to a Twitter message from a BuzzFeed reporter, Rosie Gray, who wrote that Mikulski was trying to keep the other senators from asking the director of the National Security Agency, Gen. Keith Alexander, questions about the agency’s data mining programs. "There is no attempt here to muzzle," Mikulski said after reading the message. Then she smiled and held up her smartphone. "So, Rosie, it’s an open hearing, hi, look forward to keeping in touch."

A former social worker whose first elected job was on the Baltimore City Council (a move that appalled her father, who argued that he had spent a lifetime selling bologna at the family grocery to avoid such career choices for his children), Mikulski was elected to the House in 1976 and to the Senate a decade later.

She still talks at length on the Senate floor and in committee meetings about her late father. She recalls how he paid for her to attend Mount Saint Agnes College (now a part of Loyola University Maryland), even after a devastating fire in his store, and how he struggled with Alzheimer’s disease. She keeps her mother’s kitchen table in her elegant hideaway not far from the Senate floor, because, she said, it reminds her of home.

Before voting against a recent amendment that would have reduced federal subsidies for people buying health insurance, she explained her no vote for several minutes, citing what she imagined her father would say: "Barb keep fighting, you’ve got the gavel, use it. But at the same time let me and other guys like me buy that health insurance."

Her values as a spender stem, said several members, from her social activism, Roman Catholic faith and shameless Maryland boosting. She will talk for hours about the need to protect the National Institutes of Health, both because it is in her home state and because of her interest in health care.

She has no patience for attempts to gut programs for the poor, and is eager to pass her bills in part to distinguish between her priorities and those of House Republicans. "Our bills will show the difference," she said.

But with the House and the Senate deeply divided over what budget number to use — the House is working off a top line of $967 billion while the Senate budget uses $1.058 trillion — the ability of the chambers to come together to agree on spending bills and avoid a government shutdown seems increasingly elusive. "The Republicans act like sequestration is the new normal," Mikulski said. "I reject that it is."

For the 20 women in the Senate, a record, the outcome of the coming spending fight will also be the latest test of chairwomen, who now lead nine committees, another record. Mikulski is the dean, mentor and organizer of monthly dinners the women hold to talk shop and family. "When I was running, as a woman I was really a novelty," Mikulski said, remembering how 1992 was branded "The Year of the Woman" when the number of women in the Senate hit a record of seven that election year. At the time, Mikulski said that calling it the Year of the Woman "makes it sound like the Year of the Caribou or the Year of the Asparagus. We’re not a fad, a fancy or a year."

The lesson took with one of Mikulski’s protigies, Sen. Patty Murray, D-Wash., who joined the Senate in 1993 and rose to become chairwoman of the Senate Budget Committee.

"What brought Barbara here in the first place is to make her community better," Murray said. "Her community has gone from Baltimore to the country."

© 2013 The New York Times Company