Fifteen days before Boston voters elect the city’s next chief executive, incumbent Mayor Marty Walsh of Dorchester will debate his challenger, City Councilor Tito Jackson of Roxbury, in a one-hour, face-to-face encounter tonight at 7.

Moderated by Jim Braude and Margery Eagan of WGBH News, the contest will be televised live on Channel 2, and broadcast on 89.7 FM. The debate will also be streamed by and is available via Facebook. Follow on social media with #WGBHdebate.

Polls — including last week’s by WGBH News —­ show Walsh with a commanding lead. That’s consistent with precedent. No mayor seeking reelection has been defeated in 76 years, when John Hynes repelled a challenge by James Michael Curley in 1949.

Of the likely voters polled by WGBH News, 58 percent said that they would back Walsh for a second term. This strong level of support, wrote pollster Chris Anderson of Anderson Robbins Research, “[r]eflected an optimistic mood among the voters surveyed.

“Fully 91 percent of voters would ‘recommend their neighborhood to a friend,’ and 84 percent think ‘Boston is a city where hopes and dreams can be realized for people like me.'”

However, Anderson pointed out, “Respondents expressed concerns that life was not good for everybody, everywhere in the city. Just 31 percent think all neighborhoods are improving, while 52 percent say some neighborhoods are improving, but not others. More than one in ten (14 percent) say life is not improving.”

Whatever one’s perception of the state of the city, concerns about the cost of housing clearly preoccupy voters. Respondents to the WGBH News poll said it was the biggest issue facing Boston. Recent polls by WBUR and the Boston Globe registered similar responses.

To date, at least, the mayor’s race has been more about means than ends. Jackson and Walsh, one-time allies, share similar social values and political objectives. With the exception of a handful of Massachusetts’ communities — Provincetown, Cambridge, Amherst, Northampton –– Walsh and Jackson would be considered center left. In Boston, Walsh is perceived as more “centrist” and Jackson more “progressive”.

Still, a little more than a week ago, Walsh earned the endorsement of Senator Elizabeth Warren, the titular chief of Bay State progressives. Walsh helped facilitate union support for Warren early in her first campaign, months before she became the Democrats’ putative favorite for the party’s Senate nomination.

That, in a snapshot, captures the frustrations with which the Jackson campaign has had to contend: a thick web of previous relationships, and — of course –– a huge Walsh war chest. At almost every point in the campaign Walsh has enjoyed a financial advantage of at least 40 to one. Walsh has millions of dollars, Jackson thousands.

“Incumbents have enjoyed a heavily stacked deck in Boston mayoral races since the late Seventies,” said UMass Boston political scientist Maurice Cunningham. “This race is no different, with Mayor Martin Walsh enjoying a huge fundraising advantage and a ready made organization of city workers.”

Of Tuesday’s debate, Cunningham added: “Mayor Walsh faces an uncomfortable night. I expect Councilor Tito Jackson to press him on some notable problems of the past several years such as the 2024 Olympics bid and IndyCar fiasco and the freshest bad news, the NAACP's report charging the Walsh administration with lack of progress on issues facing communities of color. Jackson's challenge will be to press the case vigorously but not offensively, knowing his best political days may yet be ahead of him — just not as soon as this November.”

One of the few breaks enjoyed by the Jackson campaign was a report in Sunday’s Boston Globe headlined “NAACP grades Walsh poorly.”

Based on a soon to be released report titled “Equality, Opportunity, and Access Report Card: The Walsh Administration,” the Globe reported that the NAACP graded Walsh “harshly,” citing, among a number of factors:

“Low levels of homeownership for building wealth among blacks and Latinos; high unemployment; high levels of poverty; and low levels of minority business development and success.”

In response to the report, Walsh told WGBH News that the findings can be used as a road map to make Boston better.

From a purely political point of view, that was a shrewd response. Not only because Walsh enjoys what political professionals call momentum, but also because he enjoys support among African American voters. Black voters prefer Walsh to Jackson 45 percent to 27 percent, according to the WGBH News poll. White voters support Walsh over Jackson by a wider margin, 67 percent to 16 percent.