The National Organization of Marriage is taking heat for aggressively coming out against gender identity lessons taught at an Oakland elementary school, as part of an anti-bullying campaign. It’s just the latest campaign waged by a group that often features black pastors to help spread its anti-gay message.

NOM president Brian Brown sent a letter to supporters calling the lessons "disturbing" and that the organizers want to "embed in these children’s minds the idea that we all have a right to make up our own gender(s)." 

NOM is an organization that campaigns against same sex marriage, civil unions, and adoption by gay couples. They have notably featured public figures of color such as Alveda King, the niece of the late Rev. Martin Luther King Jr., and New York state senator Rubén Díaz, Sr. at their rallies. 

The lessons, organized by the education group Gender Spectrum, talked about gender diversity among animal species and acceptance in their effort to create more gender sensitive and inclusive environments for kids. Parents were notified of the lessons in advance, and just three families chose to excuse their children from the program.

"Nobody’s trying to influence the students to act in any specific way. We’re just saying that if a student does exhibit these behaviors that they should not be alienated, ostracized, or most of all, bullied because of it," Troy Flint of Oakland Unified School District told Fox News.

Opponents also warned that such lessons such as these could become common if SB 48, a bill that would require California schools to teach about the contributions of various groups including transgender history, becomes law.

This past weekend, Díaz’s granddaughter Erica Diaz spoke publicly for the first time against the politician’s anti-gay rhetoric.

"When I was younger, marriage equality was not an issue for me. But now, as my grandfather ceaselessly and callously comments on the issue, each and every word stings," Erica, who lives with her girlfriend and two sons told the New York Post. "My family deserves the same benefits as others."