City Controller Michael Lamb, whose campaign for mayor never seemed to find its footing, dropped out of the mayoral race today -- and endorsed Jack Wagner instead.

"Our government has to be better, smarter, and more efficient, and we're going to have to build on the strengths that we already have," Lamb said during a brief address at his campaign's Greenfield headquarters. He cited a litany of problems the city faced, including wage disparities between men and women, and racial achievement gaps in city schools. And then he said he was dropping out "because I love Pittsburgh, and a race with so many candidates is blurry and difficult for people."

"[T]he fact of the matter is there is a real choice for mayor," he continued. "I don't want the conservation for our next leader to be generalities. We need a real dialogue to ensure that we get the best possible candidate for the job. I believe the best candidate is Jack Wagner. [He] is both a friend of organized labor and of Pittsburgh's business community. And as someone who grew up in the same neighborhood as me, I know that he understands that we need to focus on our communities, as growth in all of our neighborhoods helps us all."

Wagner, he added, "is thoughtful, deliberate, he doesn't pander. And he's totally independent. He makes up his own mind."

The move may come as a surprise. Lamb's somewhat wonky, government-reform progressive campaign strongly resembled that of City Councilor Bill Peduto -- so much so that some observers worried the two men would split the votes of reform-minded voters. But Lamb backed Wagner, who has quickly become Peduto's biggest rival -- and who has already garnered the backing of unions and politicians that previously supported Mayor Luke Ravenstahl.

During a brief Q&A session with reporters, Lamb said that he spoke with Wagner over the weekend about dropping out -- a conversation Lamb says he initiated -- but none of the other candidates. He denied that there were any deals concerning his own political future, and reiterated that "There's a choice here -- Jack has great relationships both with labor and in business. Bill doesn't."

Not surprisingly, Peduto's camp responded somewhat tartly. "Voters have a clear choice to make," it said in a statement. "Pittsburgh needs a strong leader who has demonstrated a real commitment to ending waste, fraud and abuse -- someone who has revitalized neighborhoods and secured the city’s finances. We have built a new coalition of people who understand what Pittsburgh can be. I'm looking forward to continuing to earn the support of voters all over the city and working to reach this vision together."

The message was much frostier than the one Peduto issued after Ravenstahl dropped out: In that message, Peduto expressed sympathy for "how difficult of a decision this was," adding the campaign "would like to extend our sincere best wishes to Luke Ravenstahl and his family."

Lamb was the endorsed Democrat in the race, and his withdrawal would seem to make the party endorsement moot. That would mean that Democratic committeepeople are free to publicly back anyone they wish. But Eileen Kelly, who chairs the party's city committee and was on hand for Lamb's withdrawal, says she's reviewing the party by-laws to see if the party can hold another endorsement vote, so someone will have the nod from party elders.

"To my knowledge, nothing like this has ever happened before," she said.