Phil Mendelson was overwhelmingly elected chairman by his D.C. Council colleagues after Kwame R. Brown resigned in disgrace in June. (Bill O'Leary/WASHINGTON POST)

When D.C. Council member Marion Barry gave his annual pep talk about the state of Ward 8 in March, only a few white city residents were invited.

None was a council colleague.

But as Barry spoke, Phil Mendelson (D-At Large) walked into Matthews Memorial Baptist Church and sat in a rear pew. Mendelson listened as Barry (D) pitched ideas to rebuild a Southeast ward that is 94 percent black and often feels shunned by many city politicians.

“It felt good,” Barry said. “I was impressed with Phil coming in for Ward 8. We don’t have a lot of white people over here that live and work . . . but Phil was there.”

That Mendelson attended underscores the 59-year-old’s low-key approach, one that has helped him develop a following that transcends racial and geographic lines in a city often divided by both.

Mendelson, who was overwhelmingly elected chairman by his D.C. Council colleagues after Kwame R. Brown resigned in disgrace in June, is now reaping the benefits of his three-decade career. The four-term council member has not drawn a formidable challenger for chairman, even as an Aug. 8 candidacy deadline looms before a special election for the job this fall.

The controversies surrounding the 2010 campaign of Mayor Vincent C. Gray (D) have now led Mendelson to a political crossroads. As chairman, he is next in line to succeed Gray should the mayor be forced from office by an ongoing federal investigation into that election. Mendelson would become the city’s first white mayor since home rule.

Several activists and local leaders say that Mendelson would be able to smoothly transition into the role. The former activist- turned-politician is as comfortable on a couch in a Deanwood residence as he is at a picnic table in Glover Park.

“I truly believe that Mendelson has been on the right side of many critical issues in this city, and he listens,” said Rufus Mayfield, a veteran civil rights and community activist. “I think of Mendelson not as a white individual, but as an individual concerned with all areas of the city.”

Mendelson’s popularity in the African American community results from his activist upbringing, 1970s brand of liberalism, attentive constituent service, wonkiness and reputation as a humble public servant.

“I tend to think of issues in the city as issues, instead of ‘this is a concern among white voters’ or ‘a concern among black voters,’ ” said Mendelson, who added that he prefers being chairman and has no plans to run for mayor. “But I am sensitive to the fact that there are a lot of people in this city who feel it’s important that the mayor be African American.”

For years, Mendelson would drive to community meetings in some of the city’s toughest neighborhoods in his beat-up 1998 Mercury Mystique with his daughter, Adelaide. While Mendelson spoke, Adelaide, now 11, would sit in a corner or play with other children.

“It is just like she’s at home,” said Sandra Seegars, a Ward 8 Advisory Neighborhood Commission member. “That makes it seem he’s just one of us black folks and that he’s not acting like he’s above it all.”

Still, Mendelson has some critics in the black community, who note that he opposed the creation of an Emancipation Day holiday and a mayoral takeover of schools.

And despite Mendelson’s strong ties to civil liberties groups, some African Americans said that as chairman of the Judiciary Committee he enacted tougher penalties for possession of some drugs. The new penalties have disproportionately affected the black community, they said.

“He has paralyzed people regarding laws because of the penalties but didn’t make sure people got the treatment,” said Ron Moten, a co-founder of Peace­oholics, a violence-prevention organization.

A recent Washington Post poll found that Mendelson is no more popular with black voters than three of his white colleagues: David A. Catania (I-At Large), Tommy Wells (D-Ward 6) and Jack Evans (D-Ward 2). About a quarter of black voters hold a favorable view of Mendelson, while just 13 percent hold a negative view. Over six in 10 have no opinion of him, the survey found. 

But political strategists and community activists warn against underestimating Mendelson’s popularity with politically active African Americans most likely to participate in District elections.

The electoral strength of Mendelson, including winning a three-way race by better than 2 to 1 in 2010, has apparently persuaded some potential black candidates to skip the chairman’s race in November.

“Phil is just a regular guy with an appeal that doesn’t appear threatening,” said Sean Metcalf, an adviser to D.C. Council member Vincent B. Orange (D-At Large), who considered running for chairman. “He is ‘Mister Rogers’ Neighborhood’ and gets away with that . . . Vince counts on the black vote to beat people, and that strategy doesn’t work against Phil Mendelson.”

The relative ease with which Mendelson travels in the African American community can be partially traced to his upbringing as the child of an activist in Cleveland Heights, Ohio. His mother was an advocate for nursing home reform, and his grandmother was president of the Michigan League of Women Voters and a founder of the Grand Rapids Urban League.

“I would have to say my family was liberal,” Mendelson said.

But much of Mendelson’s political acumen was formed as an activist for tenant rights and environmental issues in the 1970s and 1980s. He also worked as an aide to former council members James E. “Jim” Nathanson and David A. Clarke, the council’s only other white chairman.

A native Washingtonian who became immersed in the civil rights movement, Clarke enjoyed broad black support. Howard Croft, former chairman of the Urban Studies Department at the University of the District of Columbia, said Clarke’s death in 1997 presented Mendelson with an opportunity to step in and fill a “vacuum as the white guy that African Americans could trust.”

Yet African American activists and analysts caution that that support may not necessarily transfer to a Mendelson mayoral run should he seek the office.

Although The Post’s poll found that 53 percent of residents don’t think it’s important that the city’s mayor be black, both white and African American leaders said the city’s changing demographics may lead some black to prioritize electing black candidates more so than in the past.

“People are more sensitive today to the numbers game,” said former council member Carol Schwartz, who is white and enjoyed considerable black support during her four terms in the 1980s and 1990s.

Doris Cooper, 86, former president of the Dupont Park Civic Association in Ward 7, said Mendelson is the only council member “to pay attention” to her group’s meetings and complaints.

When asked whether she would back a Mendelson candidacy for mayor, Cooper paused, then said his race “may matter somewhat” due to the adage “the white man takes over and he keeps the black man down.”

“But you know what? For Phil Mendelson, it wouldn’t matter to me,” she said.

Peyton M. Craighill and Scott Clement contributed to this report.