Will teachers offended by the crusading film “Waiting for Superman” make their voices heard? A first attempt has fizzled, so far.

The film’s negative portrayal of teachers unions has drawn criticism from, among others, teachers union president Randi Weingarten. So when Donors Choose, the website that helps match small donors with teachers seeking to fund classroom projects, sent out an email to its members asking them to pledge to see the film, a teacher who blogs at the site Accountable Talk was upset.

“Never mind that if the film makers get their way, you most likely won’t have a classroom or a job, so your need for project funding will be drastically reduced,” he wrote. He cancelled his membership with the site and urged others to do the same. A few other bloggers took up the call, and a Facebook group called “Boycott Donors Choose” currently has just over 35 members.

But Julie Lacouture, Donors Choose’s director of program expansion, said this week that just four teachers have cancelled their membership explicitly because of the group’s involvement with “Waiting for Superman” — compared to more than 29,000 people who have pledged to see the film, according to its website.

Anyone who pledges to see “Waiting for Superman” on its website receives a five dollar gift certificate to Donors Choose. The site raised funds for the pledges from its current roster of supporters, Lacourture said. She said that Donors Choose’s aim in partnering with the filmmakers is to spark a discussion about how to improve education, and to harness the interest of movie-goers into direct aid to classrooms, not to take aim at teachers unions.

“I don’t think we’re taking a side by doing this,” she said.