Last year, Republican congressional candidate Richter Elser ’81 ran neck-and-neck in New Haven against Charlie Pillsbury ’72, who differed with him on most major issues. On Election Day, Elser out-polled Pillsbury by only 14 votes in the Elm City.

But Pillsbury is not a Democrat, and he was battling Elser for a second-place finish far behind incumbent Rosa DeLauro. Instead, Pillsbury ran as a nominee of the Green Party — a political organization that has begun to rival the New Haven Republicans as the largest opposition party in the city.

While the Greens remain much less powerful than the Democrats — who have won every mayoral election since 1953 and control 26 of 30 seats on the Board of Aldermen — the party is seeking to increase its base during this November’s elections. With Ward 2 Alderwoman Joyce Chen ’01 and Ward 9 Alderman John Halle already representing the Greens in City Hall, party officials believe they can elect at least two more Green Party aldermen this fall.

Halle, who is also a music professor at Yale, said the party — best-known for supporting Ralph Nader in the 2000 presidential elections — has begun to focus on local elections as a means of growing the party on a national level.

“The advantage to running locally is that for the most part, and in places like New Haven in particular, we are the second party,” Halle said. “We’re the only competition that’s out there, — so we’re providing the alternative.”

Both nationally and locally, the Greens have focused on providing outspoken opposition to the political establishment. The national party’s Web site, for example, touts the Greens as the only party to publicly oppose the war in Iraq and includes an online poll asking whether President George W. Bush should be impeached.

But while Halle said the Greens had succeeded in passing some environmental legislation, he said the party is not yet strong enough to push many of its major priorities in the New Haven Board of Aldermen. Instead, he said the party often tries to call attention to issues that might otherwise be ignored.

“We don’t have much negotiating power,” Halle said. “When there are 26 Democrats, opposition is, most of the time, symbolic.”

In other cases, the Greens have found themselves allied with the Democratic Party. A resolution introduced by Halle opposing military intervention in Iraq passed the Board last October by a 24-2 margin. Halle said the Greens have even turned away some Democratic politicians who have informally discussed switching into the party.

The wide range of views within the New Haven Democratic Party — illustrated by criticisms Ward 28 Alderman Brian Jenkins leveled at fellow Democrat and Mayor John DeStefano Jr. Monday night — has led the Greens to carefully choose the wards in which it fields candidates. Pillsbury said the Greens have chosen not to field a candidate against DeStefano in part because they feel DeStefano has adopted many progressive policies.

“What we have seen, frankly, is a mayor who has become more green the longer he’s in office,” Pillsbury said. “We may not have to run a mayor for office if the mayor keeps adopting a Green Party platform on some issues.”

Both Halle and Chen said they did not know how many aldermanic candidates would run on the Green ticket in November. Pillsbury announced earlier this year that he would run for alderman in Ward 19 against incumbent Democrat Alfreda Edwards, and Chen said she thought it was “very realistic” for the party to double its representation in City Hall.

Mike DeRosa, co-chair of the Connecticut Green Party, said local campaigns in New Haven are typical of the party’s efforts in progressive-leaning cities across the country. He said electoral success in New Haven and Hartford — as well as double-digit showings in elections for the General Assembly — are good signs for the future of the party.

“I believe that this is an indicator that this party is not going to go away,” DeRosa said. “I think the message that Democrats and Republicans have to hear is that there are many people who not only support a Green Party but a Green movement.”

But despite the party’s recent success, Democratic Town Committee Chairwoman Suzie Voigt said she did not see the Green Party as the primary opposition for New Haven Democrats given the city’s efforts to gain additional state and federal aid.

“I’m not more focused on the Greens than on the Republicans,” Voigt said. “I think the biggest concerns that Democrats should have is the Republican Party in Hartford and the Republican Party in Washington.”