Two years into a surge of book bans across the United States, Florida is a hot spot in the clash over what reading material is appropriate for children, with laws that have greatly expanded the state’s ability to restrict books.

Historically, books were challenged one at a time. As bans in schools and libraries began increasing nationally in 2021, efforts were largely local, led by a parent or a group. But over the past year, access to books, particularly those touching on race, gender or sexual orientation, became increasingly politicized. With that came an increase in legislation and regulations in some states and school districts that affected which books libraries could offer.

The shift is particularly evident in Florida, where Gov. Ron DeSantis, a Republican-controlled Legislature and a rapidly growing network of conservative groups aligned to pass three state laws last year aimed, at least in part, at reading or educational materials. Among the books removed from circulation in one of the state’s school districts are Toni Morrison’s “Beloved,” and Margaret Atwood’s “The Handmaid’s Tale.”

The policies have energized Mr. DeSantis’s supporters and are part of the platform from which he is expected to run for president.

Proponents of the restrictions say their aims are to protect students from inappropriate materials and to give parents more control over their children’s education. In focusing on “parents’ rights,” Mr. DeSantis is trying to build on the popularity he amassed when he resisted Covid-19 restrictions, particularly in schools. The push is a signature part of the conservatism he is showcasing in Florida. His Parental Rights in Education law, for example, constrains instruction on gender and sexuality, which has led some districts to remove books with L.G.B.T.Q. characters.

Some teachers and librarians say the policies are vague, with imprecise language and broad requirements, leading to some confusion. But they are trying to comply. Violation of the law could be a third-degree felony; in general, such crimes are punishable by up to five years in prison.

In January, when the new guidelines went into effect, some teachers removed or covered up books that had not been vetted by certified media specialists, whose approval is now legally required. Others are not ordering titles that could draw complaints. Some educators emptied shelves or pulled collections until the titles could be reassessed.

“It is a whole new level of fear,” said Kathleen Daniels, the president of the Florida Association for Media in Education, a professional organization for school librarians and media educators. “There are books that are not being selected because they have been challenged.”