California Governor Jerry Brown has signed a controversial gay history bill into law.

Senator Mark Leno's FAIR Education Act mandates the inclusion of the historical contributions of gay, lesbian, bisexual and transgender Americans in the state's textbooks. As the country's most populous state, California's move could set the tone for textbooks throughout the nation.

Starting as early as the 2013-2014 school year, the California Board of Education and local school districts will be required to include the curriculum in their lesson plans.

Brown, a gay rights ally, signed the bill on Thursday.

While the Democrat had kept mum on the legislation, it was widely believed that he backed the measure. Supporters said the bill would help ease the bullying gay teens face in the classroom.

Opponents of the bill had labeled it an attack on the family. Randy Thomasson, the head of the Christian conservative group Save California, called the bill “sexual indoctrination.”

“Why do we say that? Because it would take a lie and turn it into the truth,” Thomasson explained during a recent appearance on The Christian Broadcasting Network (CBN).

“Children should not be told to admire quote lesbian, gay, bisexual, transgender Americans as role models, because this would result in children as young as kindergarten being told that homosexuality, bisexuality is good and natural when there is no gay gene, and healthy when it is unhealthy behavior. And it would be something that they would be told to support and perhaps even think about for themselves.” (The video is embedded in the right panel of this page.)