California Gov. Gavin Newsom signed a bill Monday to ban school boards from rejecting textbooks based on their teachings about the contributions of people from different racial backgrounds, sexual orientations and gender identities.

Newsom called the measure “long overdue.”

“From Temecula to Tallahassee, fringe ideologues across the country are attempting to whitewash history and ban books from schools,” Newsom said in a statement. “With this new law, we’re cementing California’s role as the true freedom state: a place where families — not political fanatics — have the freedom to decide what’s right for them.”

The bill takes effect immediately.

The topic of banning and censoring books has become a U.S. political flashpoint, cropping up in states around the country. Many of the new restrictions enacted by conservative-dominated school boards have been over textbook representations of sexuality and LGBTQ history.

The California bill garnered heightened attention when a Southern California school board this summer rejected a social studies curriculum for elementary students that had supplementary material teaching about Harvey Milk, who was a San Francisco politician and gay rights advocate.

A 2011 state law requires schools to teach students about the historical contributions of gay, bisexual and transgender Americans.

Newsom threatened the school board with a $1.5 million fine and the board later voted to approve a modified curriculum for elementary students that met state requirements.

The new legislation bars school boards from banning instructional materials or library books because they provide “ inclusive and diverse perspectives in compliance with state law,” according to a press release from Newsom’s office.

The bill cleared the state Legislature after intense debates about what role the state should have in curricula approved by local districts and how lawmakers can make sure students are exposed to diverse and accurate portrayals of history.

Newsom also signed a bill Monday to increase penalties for child traffickers.

Democrats in the Assembly Public Safety Committee blocked the proposal earlier this year. Some lawmakers initially opposed it because they were concerned it could inadvertently punish victims of child trafficking.

After it was blocked, Newsom weighed in with his disapproval of the bill’s failure to advance, and lawmakers revived it. Republican state Sen. Shannon Grove, who authored the bill, later amended the bill to protect victims from being criminalized.