The Republican governor of Florida, Ron DeSantis, has signed into law a bill that forbids instruction on sexual orientation and gender identity in kindergarten through third grade, a policy that has drawn intense national scrutiny from critics who argue it risks marginalizing LGBTQ+ people.

LGBTQ+ advocates, students, Democrats, the entertainment industry and the White House have denounced what critics have called the “don’t say gay” bill. The issue has led to a clash between DeSantis and Disney, a major player in the Florida tourism industry.

But the legislation has also pushed Florida and DeSantis, a potential 2024 presidential candidate, to the forefront of the US culture wars.

DeSantis and Republicans say the measure is reasonable and parents, not teachers, should broach subjects of sexual orientation and gender identity with children.

Joe Biden hit back, saying that: “Our LGBTQI+ youth deserve to be affirmed and accepted just as they are.”

The Democratic US president’s full tweeted statement read: “Every student deserves to feel safe and welcome in the classroom. Our LGBTQI+ youth deserve to be affirmed and accepted just as they are. My administration will continue to fight for dignity and opportunity for every student and family — in Florida and around the country.”

DeSantis signed the bill on Monday after a news conference at the Classical preparatory school in Spring Hill, north of Tampa. The school was founded by Anne Corcoran, wife of the state education commissioner, Richard Corcoran, the Gainesville Sun reported.

“We will make sure parents can send their kids to school to get an education, not an indoctrination,” DeSantis said before signing.

He and other speakers stood at a podium affixed with a placard reading “Protect Children/Support Parents”.

“Overwhelmingly, parents oppose injecting this kind of materials into their kids,” the governor said while holding up what he said were “transgender educational materials”, according to local media.

DeSantis said many in Hollywood opposed the Florida bill.

“If the people who held Harvey Weinstein up oppose us on parents’ rights, I wear that like a badge of honor,” he said, referring to the disgraced movie producer who was found guilty of rape.

“I’m not backing down,” DeSantis added.

Critics say the Florida law is so vaguely worded that speech could be muzzled throughout public schools.

The bill states: “Classroom instruction by school personnel or third parties on sexual orientation or gender identity may not occur in kindergarten through grade three or in a manner that is not age appropriate or developmentally appropriate for students in accordance with state standards.”

Parents can sue school districts over violations.

“We insist that parents have a right to be involved,” DeSantis said.