Americans have found a book they just can’t put down — any book, as long as it’s about President Donald Trump.

Bob Woodward’s “Fear,” Michael Wolff’s “Fire and Fury,” James Comey’s “A Higher Loyalty,” and Omarosa Manigault Newman’s “Unhinged” have all topped the nonfiction best-seller charts this year — with Woodward's title selling 750,000 copies through the end of its first day on sale, publisher Simon & Schuster reported.

Copies of the book "Fire and Fury: Inside the Trump White House" by author Michael Wolff at the Book Culture book store in New York on Jan. 5, 2018. Shannon Stapleton / Reuters file

"We haven’t seen an adult title sell this quickly in over three years," said Liz Harwell, senior director of merchandising, trade books at Barnes & Noble, noting that the White House exposé has had the "fastest sales for an adult title since Harper Lee’s 'Go Set a Watchman' was released in July 2015."

The soaring market in political titles is a stark contrast to 2008, the year President Barack Obama was elected, when the year's best-sellers on Amazon included Eckhart Tolle’s self-help book, “A New Earth: Awakening to your Life’s Purpose” and David Zinczenko's latest volume of "Eat This, Not That."

The pre-orders for Woodward's book were "off the charts," Jonathan Karp, president and publisher at Simon & Schuster, told NBC News. "The book is going to be No. 1 in the U.K., Canada, Australia and even India. We are reprinting in all these countries, it’s going to be a global phenomenon."

“This is a hinge in American history and a lot of readers and voters are trying to figure out how to turn the country in the direction they think it should go,” he said.

But it isn’t just books by critics of the Trump administration that are hot. Some titles defending the president have also been big sellers. “Liars, Leakers, and Liberals,” by Fox News Channel personality Jeanine Pirro, hit the No. 1 slot on Amazon when it was released in July. “The Russia Hoax,” by Gregg Jarrett, a former Fox News Channel anchor and current contributor, hit No. 1 in early August.

While the overall book market is projected to rise 2 percent this year, the political book category is already up 25 percent, according to NPD Bookscan, which tracks print books. The data analytics firm reported that 6.9 million copies of political books were sold from Jan. 1 until the first week of September, versus 5.5 million at this point last year.

And print books are only part of the story: Audiobook sales are also soaring, up 20 percent in the first eight months of 2018, according to the Association of American Publishers. E-book sales — down 8 percent during the first quarter — saw sales of political e-books rocket by 106 percent, largely due to “Fire and Fury,” which was released in January.

Unsurprisingly, there's a flood of new political books on the horizon, including “Mr. Trump’s Wild Ride,” from CBS News chief White House correspondent Major Garrett; “Them,” by Sen. Ben Sasse, R-Neb., which comes out next month; and "Where We Go From Here," by Sen. Bernie Sanders. I-Vt., which will hit the shelves one week after the midterm elections.

Adam Bellow, editorial director of All Points Books, the political imprint at St. Martin's Press, told NBC News: “Ever since Hurricane Trump made landfall in 2016, it’s been an unusually exciting time to be in political publishing. Both parties are in total disarray. Political identities are shifting. Familiar ideas are being challenged and many people are rethinking their assumptions. So even with increased competition from other media, interest in books is exploding.”

Trump has said that his presidency has been good for the economy, and “with regard to books, Trump's claim is accurate,” said Simon & Schuster's Karp.