Muriel Bowser gets a hug of congratulations from Judi Gold, who is Bowser’s constituent services coordinator, after winning Tuesday’s general election. (Michael S. Williamson/The Washington Post)

A day after winning the D.C. mayor’s office, Muriel E. Bowser claimed a “clear mandate” from the city’s voters.

How she intends to use it is less clear.

At her first news conference as mayor-elect, Bowser said her convincing victory was a vote for a “fresh start” — repeating the theme of her 20-month campaign. Beyond that, she spoke in terms of expectations and aspirations at the National Press Club on Wednesday, not in terms of concrete actions.

“This is the resounding message that we got . . . that we love the progress that the city is making,” she said. “Nobody is nostalgic for the days when we were broke and the streets were unsafe and we were the butt of jokes across the nation. So people love the progress that we’re making, but they want to make sure we’re getting ready for a future that includes 150,000 more people.”

Hot-button issues Bowser will probably have to tackle early in her tenure percolated all around her Wednesday.

D.C. Council member Muriel E. Bowser (D-Ward 4) won big Tuesday to become the next mayor of Washington, D.C., defeating independent candidates David A. Catania and Carol Schwartz in a hard-fought contest. (NBC Washington)

A block away, at the John A. Wilson Building, her soon-to-be-former colleagues on the D.C. Council started digging deeply into a controversial deal to build a professional soccer stadium in Southwest Washington. At least one Republican member of Congress said he was determined to overturn the marijuana legalization measure approved by voters Tuesday.

And outgoing mayor Vincent C. Gray (D) forged ahead with a controversial school boundary overhaul and a plan to potentially rent out entire hotels to house homeless families this winter.

When she takes office Jan. 2, Bowser can claim to hold broad support across the city’s more than 650,000 residents. Her victory was more expansive than polls and political observers had anticipated, given the aggressive campaigns waged against her by independents David A. Catania and Carol Schwartz — both veteran politicos with decades of experience and name recognition between them.

Bowser won five of the city’s eight electoral wards, losing the other three — wards she had won in the Democratic primary — by relatively narrow margins. And the 32-percent voter turnout was also higher than a record-low primary showing had foreshadowed.

Election-night tallies put Bowser’s victory margin at 19 percentage points — significantly more comfortable than the closest-ever 1994 general election between Schwartz, then a Republican, and Democrat Marion Barry. Still, the 54 percent support Bowser won is still the least enjoyed by any incoming mayor in 40 years of D.C. home rule.

D.C. Council member Jack Evans (D-Ward 2), who lost to Bowser in the primary, said Bowser can rightfully claim a mandate — “she got a lot of votes,” he said — but a mandate mainly to keep the city on its current trajectory.

“What everybody is saying is, ‘Stay the course,’ and that’s basically what she was running on,” Evans said, adding that there is still room for aggressive reform on the issues of schools, jobs and affordable housing.

But, he said, “There is no mandate for radical change in any area shown in this election. Quite the opposite: People who elected her are pretty much saying, ‘Steady as we go.’ ”

That approach would be in contrast to the D.C. politician with whom Bowser is most identified.

After winning a sweeping victory in the 2006 Democratic mayoral primary, Adrian M. Fenty unveiled a plan to take over the D.C. Public Schools, which were then in the hands of an elected school board — an initiative he had not previously floated on the campaign trail.

Fenty spent a good deal of the political capital he’d earned in his every-precinct victory on the school-takeover plan, which helped establish education as his signature issue. But his sharp focus on that issue also proved divisive in the long run.

Bowser said “there may be” an initiative of similar sweep that she undertakes in her first 100 days in office, but she gave little indication Wednesday what it might be. A policy platform released in September includes nothing quite so ambitious.

“If you look at her campaign, it didn’t appear that she had an overriding passion on any major issue,” said former D.C. Council member Kevin P. Chavous. But that “blank slate,” he said, could be an opportunity as much as a weakness in a city with persistent divisions and seemingly little stomach for radical change.

“If she tried to address all parts of the city and be a visible, engaging, hands on-mayor, I think she can bring the city together in the way that others couldn’t,” said Chavous, who represented Ward 7 as a Democrat from 1993 through 2004. “There’s just all this tension, and where she could really make her mark is in finding a way for people to really coalesce as Washingtonians. I think that’s something she could do that few others could do at this time.”

During her news conference Wednesday, Bowser did highlight the city’s affordability issues, particularly in housing, and made note of legislation she had passed allowing for new public-private infrastructure partnerships. Otherwise, Bowser reacted to the news.

She said she wanted the city to develop a system for the sales and taxation of marijuana before implementing an initiative that legalized the possession but not the sale of small amounts of cannabis.

She expressed ongoing reservations about the public-private deal to build a soccer stadium, though she said she thought the council could “get to a deal that works for taxpayers” before assuming the mayoralty.

And she said she was prepared to roll back the implementation of the school boundary overhaul. “I’m not of the belief that [if] anything happens in the next 58 days, it can’t be undone or tweaked in the first 100 days,” she said.

Bowser said more detail on her plans will be developed by a transition team that will begin its work in the coming days. She said she was “in an unprecedented space” given the competitive nature of the general election, which made embarking on an early transition politically perilous.

“We did not do that,” she said. “We were focused on winning our election, and we did.”

But behind the scenes, the seeds of a transition effort have been underway for several weeks, led by former Pepco executive Beverly L. Perry, according to people familiar with the activity.

Perry, among other things, met with outgoing Mayor Vincent C. Gray last month and recruited members of the transition team. Bowser introduced her Wednesday as one of five co-chairs of her transition committee, with additional leaders to be named later this week.

In a statement late Tuesday, Gray said he hoped that Bowser would “continue on the positive, upward trajectory we’ve set” and had “directed all in my administration to work with the incoming administration to ensure a smooth transition.”