Party-minded progressives had much to celebrate last week, trouncing Rudy on the Charter, winning the traditionally Republican Upper East Side City Council seat–and losing spectacularly in Sheepshead Bay. That’s right–leaders of the Working Families Party and Green Party say that their support of peace activist Sonya Ostrom paid off, even though she netted only 13 percent against incumbent Democratic City Councilman Mike Nelson, who won with 80 percent.

“I was pleased,” said Ostrom, a former teacher and head of Metro Peace Action, a well-established local anti-war group. “I did very well, all things considered.”

“It was totally successful,” agreed Working Families Party director Dan Cantor. “I’d be shocked if [Nelson] doesn’t vote pro-tenant from now on.” Tenant activists had targeted Nelson because he voted in favor of the controversial lead paint bill this summer.

But Tuesday night wasn’t just about partying. The race also revealed the tensions between the Working Families and the Greens, troubles that could hurt the chances of grassroots candidates winning over the 37 council seats that–thanks to term limits–will open up in 2001.

On the surface it’s about strategy. The labor and organizing-backed Working Families tends to be more pragmatic, while the environmentalist Greens are more concerned with principle. More deeply, it’s a cultural divide between the different types of people in either party: well-read left-wingers in one, and bearded blue-collar types in the other.

So, between election-night riffs on Lawrence Ferlinghetti, jazz and encounter psychology, some of Ostrom’s Green Party supporters sniffed at the Working Families Party, charging that it hadn’t done enough for their candidate-specifically, that the WFP didn’t provide enough poll workers. At polling sites, Greens urged voters to cast their ballot for Ostrom on the Green Party ticket, rather than the new Working Families line.

But Ostrom credited the WFP’s work, adding that “they worked independently–let’s put it that way.” Forty-two percent of Ostom’s vote came on the WFP ballot line.

WFP members made similar gripes about the Greens. In fact, several disaffected Greens have recently defected to the Working Families Party, complaining that the environmentalists are irrelevant because they don’t appeal to labor or black votes. (To their credit, the Greens did manage to elect a black councilwoman in Hartford last Tuesday.)

Meanwhile, despite the fact that it provided 10 percent of new Upper East Side councilwoman Eva Moskowitz’ vote, the WFP was a no-show in the media and even with the Board of Elections, which initially told City Limits that votes on the WFP ballot line were for “the freedom/socialist party.”

But Working Families now has chapters in East New York, the East Side, South Brooklyn and Crown Heights and is considering Northeast Queens or Far Rockaway as the next target. Most importantly, this year’s races show that these small independent parties can mobilize an important fraction of the vote, giving them influence with the reigning Democrats. “It shows that there’s a real market out there for sensible progressive politics,” said Cantor.