An East Boston casino proposal is right where supporters don’t want it to be — in the middle of the mayor’s race.

Suffolk Downs was supposed to have the inside track when it came to winning a lucrative casino license from the state. But earlier this year, the proposal lost some momentum when Boston Mayor Thomas M. Menino — the plan’s most prominent political backer — said he would leave office after 20 years. The mayor also battled a series of health setbacks and his attention was further diverted by the Boston Marathon bombings.

While everyone waited to hear the terms of a deal between casino developers and the city, the mayor’s race got underway. Now, one mayoral hopeful — Bill Walczak — is questioning the very premise for developing an urban gambling palace.

“Boston is better than a casino,” Walczak told the Globe. “There’s better ways of building jobs. There’s better ways of building up the city.”

Charles L. Clemons Jr., another candidate, also opposes a Boston casino. But Walczak stands alone in speaking out so strongly against it.

Other candidates could be starting to hedge their bets. When the Globe sent out a questionnaire seeking positions on multiple issues, two candidates — City Councilor John R. Connolly and Suffolk County District Attorney Daniel F. Conley — blanked this query: “Do you support the Suffolk Downs casino?”

Conley previously said he supports a citywide vote on gambling, versus a vote restricted to East Boston, a position that has already cost him support. State Representative Carlo P. Basile of East Boston switched from Conley to Connolly, who previously said the vote should be limited to East Boston.

Those candidates who mirror Menino’s position — yes on Suffolk Downs and no on a citywide vote — include City Councilors Felix G. Arroyo, Robert Consalvo, and Michael P. Ross; Charlotte Golar Richie, a former Menino administration official; and state Representative Martin J. Walsh.

With Menino behind it, a casino license for Suffolk Downs seemed like a certainty. But Las Vegas developer Steve Wynn dramatically changed the playing field with a surprise proposal for a $1.2 billion casino in Everett. He quickly reached agreement with city officials and won voter approval in June. Foxwoods Resort Casino has also joined an effort to build a suburban gambling resort in Milford.

Now, the Boston casino license bid is playing out against the mayoral election — the first in two decades without Menino on the ballot. Once Suffolk Downs hashes out a host agreement with Boston, the proposal must go before voters within 60 to 90 days. Under state law, the vote will be limited to East Boston, unless the mayor and City Council call for a citywide referendum.

To further complicate matters, it should be noted that five city councilors are also running for mayor. The Boston Herald reported that one of them — Arroyo — has hired political consultant Doug Rubin, whose firm, Northwind Strategies, also represents Suffolk Downs.

The preliminary election is scheduled for Sept. 24. The top two contenders face off on Nov. 5. That political calendar is stirring speculation that an announcement of the long-awaited agreement between Boston and Suffolk Downs might be held up so the 60 to 90 day window falls while Menino still holds office — but after the mayor’s race is over.

Of course, those are process issues, which ignore the heart of the doubt raised by Walczak: Does Boston really need a casino? Is it the best path to job creation?

There’s no sign — yet — that casino-related questions are catching fire with voters. But the potential is there. In March, a Globe poll found that 44 percent of respondents favored a Suffolk Downs casino and 37 percent opposed. A poll released last month by Suffolk University and the Boston Herald found that 49 percent of those surveyed support a Suffolk Downs casino and 43 percent oppose it. Whether that margin of opposition is a rallying cry for a mayoral candidate is unclear — but Walczak is banking on it.

Walczak’s opposition is rooted in the personal. He describes his mother and aunt as gambling addicts. He also said he witnessed the downside of gambling in his professional life as a health care executive.

The real question for Boston voters is whether the economic upside is as great as promised — and worth the downside.