In a video endorsing Christine Quinn for New York City mayor, gay rights activist Evan Wolfson says Quinn knows how to explain how things work.

Wolfson is the 56-year-old founder and executive director of Freedom to Marry, the nation's largest single-issue group promoting marriage equality.

In a 60-second video released Thursday by the Quinn campaign, Wolfson looked back at 25 years of activism.

“As I've known her, I've been struck by how much she has come from being this activist, this advocate, this fighter to being a leader,” Wolfson said. “To being someone who can explain to people how it works, what we need to do. Not just give the quick and easy answer, but the real explanation for how we're going to get New York and America to be better.” (The video is embedded on this page. Visit our video library for more videos.)

After leading Democratic mayoral primary polls for months, Quinn came in third in a recent poll.

“You know, you don't end up the first openly gay and woman speaker of the City Council 'cause you're the frontrunner,” she told BuzzFeed.com. “I got that position – won it – as the underdog. And I'm going to fight over the next 10 days and get into the runoff because New Yorkers deserve a fighter as mayor.”

(Related: George Takei endorses Christine Quinn for NYC mayor in new video.)