Zach Wahls has said he first heard political attacks against gay marriage during the 2004 Republican National Convention.

Wahls is the University of Iowa student who defended his two-mom family at an Iowa House hearing considering a proposed measure which would repeal the state's gay marriage law by defining marriage as a heterosexual union in the Iowa Constitution. A video of Wahls' testimony attracted more than 18.3 million views to become the most-watched video in 2011.

Wahls, now 21, has penned a memoir about his two-mom family titled My Two Moms: Lessons of Love, Strength, and What Makes a Family.

In an interview with the BBC to pitch his book, Wahls said he first heard politicians attacking the relationships of gay and lesbian couples during the 2004 Republican National Convention.

“I'll never forget the first time I was really exposed to that kind of political rhetoric. It was 2004 and I was watching the Republican National Convention. They would start off by saying something that I totally agreed with, you know, how important marriage is as an institution. How important it is to give children examples of responsibility and safety and security. And then they would pivot – and that's why we have to protect traditional marriage,” Wahls said. (The video is embedded on this page. Visit our video library for more videos.)