Lang, Brown and Williams want to send a message to Alexander foes. (Kemry Hughes/Tom Brown for Ward 7)

The mathematics of the Ward 7 D.C. Council race are pretty simple: In the Democratic primary, there’s a significant group of voters looking for an alternative to incumbent Yvette M. Alexander, but she has four challengers who could split the opposition and help guarantee Alexander a second full term.

Tom Brown, fresh off a number of major endorsements, is making a big effort now to sell himself as the candidate for Alexander opponents to converge behind, hosting a rally today to tout his growing support.

The rally featured two strange-ish bedfellows in D.C. Chamber of Commerce CEO Barbara Lang and AFL-CIO Metro Washington Council President Joslyn Williams.

Big Business and Big Labor have swum in the same pool before on occasion, but to have them allied against a sitting incumbent is rather something. Representatives of the D.C. for Democracy progressive group and the Gertrude Stein Democratic Club also appeared to tout their Brown endorsements.

I was unable to make it to Deanwood’s Living Faith Baptist Church for the rally, but Lang said in a telephone interview that while “unusual” for her to share a stage with the city’s biggest labor group, her members are supporting Brown’s pro-small-business message.

Brown, 45, runs a workforce development nonprofit, Training Grounds, that has seen significant corporate support.

Alexander, she said, “has not been anti-business, I wanted that to be very clear ... It was that [Brown’s] messaging and what he stood for seemed to resonate more with our political action committee members.”

She said it was “fair” to characterize today’s really as an attempt to gather the Alexander opposition behind Brown. “Whenever you have a crowded field like that, it divides those who are opposed and allows the incumbent to win,” she said.

Alexander and Brown are joined on the ballot by minister William Bennett II, lawyer/scion Kevin B. Chavous and State Board of Education member Dorothy Douglas.

UPDATE, 8 P.M.: Williams cites a “lack of leadership” on Alexander’s part for her losing the labor endorsement she enjoyed in 2008. “We thought she would show leadership,” he said. “She did not show the leadership we were looking for,” citing broken promises on votes involving noise restrictions and the Betty Noel appointment.