As acting Boston mayor, Kim Janey appeared to have a leg up in the race. So how did she lose?

Acting Mayor Kim Janey attracted a wave of national positive press when she took the post.Jessica Rinaldi/Globe Staff/file

It’s a question that still hangs over the city’s politics a week after a historic preliminary election: How did Acting Mayor Kim Janey, armed with the benefits of that office, fail to advance to the Nov. 2 general election?

For more than five months, she had the unique leg up of being able to show voters, in real time, how she would do the job, while her rivals could only issue press releases about what they might do, given the chance. She attracted a wave of national positive press when she ascended to City Hall’s fifth floor corner office — the first Black person and first woman to occupy the job — and emphasized equity in policy decisions throughout the summer.

But the built-in advantage wasn’t enough. Janey came in fourth, with 19.5 percent of the vote. The top two candidates, City Councilors Michelle Wu and Annissa Essaibi George, will face off in November, and Janey’s tenure will end later that month when the new mayor is sworn in.

In the aftermath, the theories are myriad as to why Janey fell short despite her political head start. Was it failed messaging? A less than robust ground game? Turnout? Or was it simply that not enough white people in Boston, a city with an extensive history of racism and segregation, wanted to vote for a Black woman to be mayor?

Data from the MassINC Polling Group show that white-majority precincts had a higher turnout than more diverse precincts. And of the 50 precincts with the highest turnouts, Janey did not win a single one, according to that group.

Interviews with analysts, supporters, and critics reveal a picture of a candidate who tried to wrestle with the complex problems of the city while also building a citywide campaign infrastructure for the first time, a task that proved to be too much for a candidate who had only run twice for a district council seat. Some observers believe Janey leaned too far into the mayoralty and her quasi-incumbent status — she tried to excise the “acting” part of her title immediately upon entering the office — during an election that was fundamentally about change. Others say she failed to adequately communicate her progressiveness, didn’t translate her day-to-day work into ballot box success, and didn’t capitalize on the momentum she had.

Janey has so far been tight-lipped about her loss, ignoring a question last week about what she considered to be the deciding factor in the campaign.

One critic, Paul Parara, a local radio host known as Notorious VOG, is among those who thought Janey failed to convey why she was pursuing a full mayoral term clearly enough.

“Why was she running?” he said. “She never made a justification. . . . Andrea Campbell had made a good argument about why she’s in the race. Being acting mayor is not a reason to run for mayor.”

Mark Horan, a political strategist who lives in Jamaica Plain but was not working for any mayoral campaign, came to a similar conclusion: Janey “didn’t seize the job and never articulated what she wanted to [do] with the office,” he said. She entered the mayor’s office as a serious progressive, but Horan thought Janey didn’t do enough to communicate those bona fides through her campaign, failing to garner more of the progressive vote she needed to win.

“She doubled down on being the incumbent in a year when voters were embracing change,” Horan said. “Her last ad felt like a tourism ad: ‘Come to Boston, everything is going great!’ That’s a tough sell amidst a pandemic and a field that was inherently about change.”

In the end, there would be no repeat of 1993. That year, Thomas M. Menino found himself in similar circumstances when as council president he became acting mayor upon the departure of Raymond L. Flynn. He rode the role to Election Day success and was mayor for more than 20 years. Many have cautioned such comparisons are overly simplistic. Not only has Boston changed, but Menino, who died in 2014, was a different politician than Janey, with more clout and City Council experience when he became acting mayor, they argue.

Joyce Ferriabough Bolling, a political strategist from Roxbury who supported Janey, rejected any comparison to the 1993 contest or the suggestion that Janey should have been considered a front-runner.

”How was it hers to lose?” she said. “First time in that position? A pandemic? A Black woman? And you feel that that’s a precedent? Ridiculous.”

Still, Janey’s role as acting mayor was seen as a significant advantage. Any mayor, even an acting one, in Boston wields enormous power and their decisions can garner daily media attention.

But as Janey, a district councilor who had never run citywide before, was contemplating whether to run for the top post, her council colleague Lydia Edwards said she gave Janey unsolicited advice. Edwards cautioned her against running for mayor, saying that campaigning for that post for the first time while also running the city for the first time was “an incredibly tall order.” To borrow a metaphor used by one local political consultant, Janey had to learn to fly an airplane while also building one.

“I don’t know if anyone can do that, especially during a pandemic,” said Edwards, who has clashed with Janey in recent months and supported Wu in the race.

Both Wu and Essaibi George had successfully run for citywide posts before, and Campbell, while a district councilor like Janey, had already been running for months by the time Janey jumped in.

Edwards recalled telling Janey, “I think you would be the greatest mayor if you don’t run.”

Janey defenders say she inherited a thorny set of problems, including the pandemic, a police department in disarray, and the rampant opioid crisis in the area of Massachusetts Avenue and Melnea Cass Boulevard. They also point to Campbell’s consistent criticism of Janey’s performance as mayor, a Globe editorial endorsing Campbell, and a relatively low and traditional turnout for a municipal election, as all hurting Janey’s chances.

David Paleologos, director of the Suffolk University Political Research Center, said Janey spent a lot of time trying to do the job of mayor.

“It showed with a 61 percent job approval, but she fell short of converting that job approval to her electability and her actual votes,” he said.

It’s a point that Doug Rubin, a political consultant who helped steer Janey’s campaign, conceded.

“Bottom line, Kim did an amazing job as mayor. She was a great candidate. I wish the campaign was able to convey more of that, more effectively. I take responsibility for that,” said Rubin. “We needed to do a better job of conveying the work she was doing and her values and her agenda.”

Additionally, multiple political observers noted that Janey did not have as robust of a get-out-the-vote operation as Wu and Essaibi George.

Rubin said the campaign knocked on 7,000 doors the Saturday before the election and prioritized that and calling voters, instead of holding signs, on Election Day. But he acknowledged that criticisms of the boots-on-the-ground field operation were valid.

Janey had a different agenda and a different set of values than her predecessor, Martin J. Walsh, and the administration that she inherited was not “her” City Hall. Many City Hall insiders did not know if they were going to be there through November, and rumors swirled for months about discord and divisions within the building between Janey’s tight group of advisers and Walsh holdovers.

“I actually think what she was able to accomplish given all of that was pretty damn impressive,” Rubin said.

While Janey did snag a key municipal labor union endorsement, some in the city’s political circles say the City Hall tensions may have hurt her campaign. The lack of full-throated support from a fair number of City Hall players, the observers said, left Janey without the traditional backbone her predecessors built their campaign apparatus on.

Others see the main causes of Janey’s failure not in her own campaign, but in Boston’s persistent racial divide, which could be seen in the turnout.

In precincts with the highest concentration of Black voters, Janey fared the best among the field, according to the MassINC Polling Group, with 46 percent support. The group’s data showed that in the whitest precincts, Essaibi George won 44 percent of the vote versus Janey’s 6 percent. Conversely, in the least white precincts, Essaibi George garnered 8 percent of the vote versus Janey’s 45 percent.

Another blow to Janey, MassInc found, was relatively low turnout in communities of color. The turnout was highest in the least diverse precincts.

“We always felt that we needed a turnout that was higher and more diverse than a traditional municipal turnout,” said Rubin. “We obviously didn’t get it.”

The Rev. Willie Bodrick, senior pastor at Roxbury’s historic Twelfth Baptist Church, where generations of Janey’s family have worshiped, said this week: “The difficulty that many Black Bostonians are struggling with is the identity of the city. Are we really moving towards a place where people, particularly those in white majority communities, are prepared for a Black mayor?”

He added, “There may be a misunderstanding of where we are as a city, and how far we have progressed as a city.”

Ferriabough Bolling, the political strategist, also noted the city’s racial divide reflected in the results.

“One step forward with two steps back, when you look at how it all shook out at the end,” said Ferriabough Bolling, who said white progressives had bailed in their support of Janey in favor of Wu.

For his part, Rubin summed up the reality succinctly.

“At the end of the day, we didn’t get the job done.”

Meghan E. Irons of the Globe staff contributed to this report.