NEW YORK—“Rich guys don’t always win.”

That’s what Mayor Michael Bloomberg, running for re-election in November on the Republican and Independence Parties’ lines, told the Working Families Party forum July 6, in response to a question as to whether or not it was fair for Bloomberg to use his billions of dollars to personally fund his campaign and outspend his opponents, who have to rely on the raising money from supporters.

Unfortunately for Bloomberg, his statement may prove true in November.

Until fairly recently, the city’s comptroller and Democratic mayoral candidate Bill Thompson, Bloomberg’s most viable challenger, seemed to be nothing more than a long shot. But in the past month or so, Thompson’s campaign has assembled what looks more and more like a winning coalition.

He is making headway by gaining significant labor endorsements while some of the unions backing Bloomberg are having problems that are not helpful to the Bloomberg campaign.

While Bloomberg has been endorsed by SEIU Local 32 BJ, for example, several staff members are saying, off the record, that they don’t expect many members of the local to work or vote for Bloomberg.

Last month Bloomberg’s campaign released a video of an endorsement of the mayor by Michael J Forde, executive director of the New York District Council of the Carpenters and Joiners of America. Since then, big New York contractors have been indicted, along with Ford and other leaders of the union, in an alleged scheme that involves payment of bribes by the companies to union leaders in exchange for allowing companies to avoid required contributions to employee pension funds. Although the union leaders involved are innocent until proven guilty the publicity is not good for Bloomberg.

Eleven of the 20 smaller unions that Bloomberg claims are supporting him are part of the district council having the problems.

Thompson, meanwhile, is racking up support from the city’s largest and most [powerful unions including both the Transport Workers Union Local 100 and, as of today, AFSCME District Council 37, the largest in the city with over 120,000 workers.

The other two unions, the United Federation of Teachers and SEIU 1199 haven’t endorsed yet but are not expected to be pulling for Bloomberg. The worst Thompson can expect from them is neutrality.

While none of them are particularly happy with Bloomberg, some say there is fear of retaliation from Bloomberg were they to endorse Thompson. The teachers, for one, have a contract that expires in October, just before the election.

District Council 37, some say, backed Bloomberg in 2005 because they felt he was certain to win anyway and there was no harm done in maintaining a good relationship with him.

In addition to labor a winning coalition in New York must include significant African American and Latino support. Thompson has already won the backing of the vast majority of African American and Latino elected officials as well as community and religious leaders.

A poll released in late July showed that Bloomberg’s lead over Thompson had dropped precipitously, to half of what it was previously. As of then, Bloomberg had a ten point lead, with less than half of New Yorkers supporting him. Most polled say they would like to see someone besides Bloomberg take the reigns, but simply don’t know enough about Thompson—yet—to make a choice.

Thompson’s broad list of endorsements, which also includes the powerful Working Families Party, will mean thousands of boots on the ground going door-to-door and making phone calls. This is in addition to Thompson’s own campaign, which has recently launched a grassroots volunteer operation.

Based on these trends, November could be a problematic month for Mayor Bloomberg.