One thought prevailed as state Representative Martin J. Walsh and Councilor at Large John R. Connolly battled for mayor of Boston: The road to City Hall would lead through the heart of the city and its southernmost precincts.
On Election Day, that appears to be exactly what happened.
Walsh was elected the 48th mayor of Boston because he won substantially more votes in communities of color than his opponent, said Steve Koczela, president of the MassINC Polling Group.
Connolly earned more votes in many areas of the city where most residents are white, neighborhoods that also saw larger numbers of people show up at the polls. While turnout overall was lower in communities of color, those who showed up voted almost three to two for Walsh.
Those votes “pushed Marty Walsh over the finish line,” Koczela said.
In the end, the difference between victory and defeat was fewer than 5,000 votes citywide, of nearly 140,000 cast.
Connolly erected a wall of support that arced along the city’s western edge and northern tip, from Charlestown to downtown and then through Back Bay, the South End, and into Roslindale and West Roxbury.
Walsh won the rest of the city, and with it the mayoral race. Voters in his base of support, parts of Dorchester and South Boston, turned out for him in droves, with more than 17,000 votes cast for the longtime labor leader.
But Walsh was able to extend far beyond that, winning neighborhood after neighborhood in communities of color, precincts that neither he nor Connolly did especially well in during the preliminary election.
That was the home base for the three candidates of color who earned the most votes during the preliminary. Charlotte Golar Richie, John F. Barros, and Felix G. Arroyo became Walsh allies during the final election, endorsements that appeared to translate into votes at the polls Tuesday.
Walsh won in many of the places where Golar Richie, Barros, and Arroyo had their best showing in the preliminary.
In September, they captured the most votes in nine of Boston’s 22 wards. Walsh topped Connolly in seven of those nine wards Tuesday.
Golar Richie, Barros, and Arroyo, for example, combined to pull in more than 60 percent of the vote in Roxbury-based Ward 12 during the preliminary election. On Tuesday, roughly 58 percent of voters in Ward 12 cast ballots for Walsh, 17 percentage points higher than Connolly.
Walsh loudly trumpeted the endorsements from his former mayoral rivals in the final weeks of the campaign, relentlessly reminding voters of their backing in television ads, campaign literature, and speeches on the campaign trail.
“It made people take a closer look at him and be more open to him,” said Judith Kurland, former chief of staff to Mayor Thomas M. Menino and executive director of the University of Massachusetts Boston’s Center for Community Democracy and Democratic Literacy. The endorsements, she said, “made people much more open to listening to him.”
Voters weighed their options a bit differently because Walsh had the backing of not just Golar Richie, Barros, and Arroyo, but most of the state’s elected officials of color. Voters may have disregarded concerns they had about Walsh or believed in his cause even more because Walsh had the stamp of approval from trusted sources, Kurland said.
Tuesday’s election results could indicate a new electoral coalition, said Larry DiCara, a former councilor and a student of Boston’s politics.
In many previous hard-fought citywide elections, “the South Boston-Dorchester axis was on the opposite side of the minority community, and this time they weren’t,” he said. “It may mean that we have a new coalition: blue-collar white folks and people of color.”
As ballots were cast on Election Day, early figures were in Connolly’s favor. Overall turnout was higher than expected, and voters in East Boston, Charlestown, Back Bay, and downtown, considered part of Connolly’s stronghold, were voting early and in force, said campaign aides and political observers.
Voters in communities of color were showing up at the polls in low numbers early in the day, and the question became: would voting pick up in those communities as the day progressed?
Then came the midday tabulations for wards across the city, including Ward 18, a massive area anchored by Hyde Park and Mattapan.
The trends in voter turnout appeared to be breaking in Walsh’s favor.
Before the election, Hyde Park had been regarded as “a real jump ball,” DiCara said.
The voter-rich area loomed as uncommitted, fertile terrain for either candidate.
The two sons of Hyde Park, Councilor Rob Consalvo and Suffolk District Attorney Daniel F. Conley, fell short during the preliminary election, leaving thousands of votes primed for the taking.
Consalvo and Conley earned more than 40 percent of the 13,960 votes cast in Ward 18, a swath of the city teeming with residents from Haiti and other Caribbean nations as well as voters of Polish, Italian, and Irish heritage. Neither Connolly nor Walsh won even 10 percent there in September.
But the region swung heavily for Walsh Tuesday, when Connolly did not win a single precinct. Walsh earned about 60 percent of 16,078 votes cast.
Hyde Park is often, incorrectly, lumped with Roslindale and West Roxbury, the neighborhood Connolly calls home, in terms of demographics and voting proclivities.
It is a notion that puzzles Larry Mayes, a political observer and former member of Menino’s Cabinet.
“It was a mystery that there was this idea that John was like de facto strong in [Ward] 18,” Mayes said. “Eighteen fell so heavily to Walsh because he earned it. He worked hard in that neighborhood. Every weekend they were there, Saturday and Sunday, for weeks. It’s just as simple as that.”
Wednesday morning, Walsh met with Menino for about 20 minutes at City Hall, where the two dissected election returns.
At a press conference later, Walsh said Menino thought the results were interesting.
“He was surprised a little bit,” Walsh said.
“I won his area, Hyde Park, which I was very happy about. I won East Boston. The mayor certainly understands this city when it comes to politics.”
And so the mayor offered the mayor-elect a bit of advice.
Walsh said Menino told him: “Go back and work the neighborhoods. Make sure you’re accessible.”
Joshua Miller and Andrew Ryan of the Globe staff contributed to this report. Akilah Johnson can be reached at firstname.lastname@example.org.