President Joe Biden delivered some funny lines at the White House Correspondents’ Dinner on Saturday night, but toward the end of his remarks, the Democrat sounded a serious note, warning that “a poison is running through our democracy and parts of the extreme press.”

To bolster his point, Biden added, “The truth buried by lies, and lies living on as truth. Lies told for profit and power. Lies of conspiracy and malice repeated over and over again, designed to generate a cycle of anger, hate, and even violence. A cycle that emboldens history to be buried, books to be banned….”

If the reference to Biden’s concerns about book banning sounded familiar, it wasn’t your imagination. Politico reported last week:

Presidential campaigns often are waged on whether or not the country is ready to “turn the page.” President Joe Biden wants his reelection bid to hinge on whether or not there is a page to turn. The president’s team has made the issue of book banning a surprisingly central element of his campaign’s opening salvos.

I’m not privy to Team Biden’s internal polling, but as the incumbent moves forward with his newly announced re-election campaign, it’s a safe bet the Democrat and his campaign operation have seen some overwhelming public opposition to book banning.

In the first ad of Biden’s 2024 run, for example, voters were told that “MAGA extremists” are lining up to take “bedrock freedoms away.” The spot, summarizing Biden’s broader message, added, “Cutting Social Security that you’ve paid for your entire life while cutting taxes for the very wealthy. Dictating what health care decisions women can make, banning books, and telling people who they can love — all while making it more difficult for you to be able to vote.”

The second ad stressed similar points: “But they’re under attack by an extreme movement that seeks to overturn elections, ban books, and eliminate a woman’s right to choose.”

But the message isn’t limited to advertising. Last week, the president delivered remarks at the 2023 National and State Teachers of the Year Celebration, telling attendees, “Let’s stand with teachers and parents against politicians who try to score political points by banning books. As a student of history, I never thought I’d be a president who was fighting against elected officials banning books. Empty shelves don’t help kids learn very much.”

A week earlier, Vice President Kamala Harris spoke at the National Action Network National Convention and took aim at “extremists across our country” who “ban books to attempt to erase America’s full history.” Soon after, she delivered remarks at Howard University on reproductive rights, taking the time to add, “Don’t think it’s not a national agenda when they start banning books. Banning books to stand in the way of teaching America’s full history so the truth can be spoken, so we can learn and do better.”

Even Miguel Cardona, the U.S. secretary of education, recently wrote an op-ed that argued in part, “I want us to enrich public schools, not ban books.”

None of this is exactly subtle. Politico’s report added, “The early focus on book banning is part of the campaign’s attempt to reinforce a broader message, said one Democratic adviser involved in the effort: Biden is the only one standing between the American people and a Republican Party determined to roll back rights and limit freedoms.”

And while the larger trend is a national issue, much of the focus of late has been on Florida, and for good reason. As a recent New York Times report explained, “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.”

Republican Gov. Ron DeSantis, no doubt aware of the fact that book bans are unpopular, has tried to condemn the concerns as a “hoax,” but the evidence to the contrary is overwhelming.

Among the authors whose work has been targeted for removal from Florida school libraries is Jodi Picoult and Nora Roberts — neither of whom is pleased.

The more outrages like these continue, the easier it will be for Biden and his allies to make the case that the problem is real; the culprits need pushback; and upcoming elections will help dictate who prevails.