CHICAGO (Reuters) - Diane Kacprowski showed up at 57th Street Books in Chicago early on Tuesday on a mission to be one of the first to snap up a copy of James Comey’s scalding memoir about his time at the helm of the FBI and his abrupt firing by President Donald Trump.

“A Higher Loyalty: Truth, Lies and Leadership” went on sale at midnight, and customers scrambled to bookstores around the country to buy the tell-all book that sparked a Twitter war between Trump and the man he fired.

“I’m buying it for the same reason I bought ‘Fire and Fury,’” Kacprowski, a 62-year-old airline employee and realtor said, referring to Michael Wolff’s scathing book about the Trump White House. “To stick it to Trump.”

She was fortunate to have arrived early. The bookstore sold out all its stock within 20 minutes of opening for business. At other bookstores, owners said sales were slower and the publisher, Macmillan, would not release initial sales figures.

Conservative commentators, such as Fox News host Tucker Carlson, have attacked Comey as partisan and indecisive in his handling of the email scandal that dogged Hillary Clinton’s 2016 presidential campaign. Others, like former Harvard law professor Alan Dershowitz, have denounced Comey for leaking memos about his discussions with Trump.

Macmillan, Comey’s publisher, ordered 850,000 copies to meet expected demand compared with Wolff’s first print run of 150,000.

At some stores, however, early sales of Comey’s book were slower than Wolff’s blockbuster.

Copies of James Comey's book "A Higher Loyalty" are pictured in a book store in the Manhattan borough of New York City, New York, U.S., April 17, 2018. REUTERS/Mike Segar

“I was very concerned that we wouldn’t have enough,” said Judy Hirsch, a saleswoman at a small, independent bookstore in New York’s Greenwich Village. It ordered 25 books but had sold only four copies by late afternoon.

In the nation’s capital, shopper Phillip Carlisle rushed to buy the book at Washington’s Kramerbooks & Afterwords Cafe when it was released just after the stroke of midnight.

“I was excited to read a book by somebody who I think is a fundamentally honest person,” said Carlisle, who described himself as a “pretty far-left person.”

Comey’s firing by Trump last year led to the appointment of Special Counsel Robert Mueller to investigate allegations that Russia meddled in the 2016 presidential election and possible collusion between Russians and the Trump campaign.

In the memoir, Comey described an intelligence briefing in which Trump and his team were told about evidence of Russia’s interference in the election. In response, the president-elect had only one question, Comey writes: “But you found there was no impact on the result, right?”

The release capped a weeklong media blitz to publicize the book. In an ABC News interview on Sunday, Comey said Trump was a dangerous and “morally unfit” leader doing “tremendous damage” to U.S. institutional and cultural norms.

For his part, Trump repeatedly hurled insulting tweets at Comey in the run-up to the release, challenging accusations made in the book and the author’s integrity.

“Slippery James Comey, a man who always ends up badly and out of whack (he is not smart!), will go down as the WORST FBI Director in history, by far!” Trump wrote early on Sunday in one of five Twitter posts aimed directly at Comey.

At The Strand in New York, Denise Thomas grabbed a copy of the book, which features a staid black cover with silver lettering, saying she hoped it would make sense of the barrage of news from Washington.

“I’m hoping to be able to sift through just one person’s telling,” said Thomas, 52, an administrative assistant from Longmeadow, Massachusetts, vacationing in New York.

“Every day there’s not only one scandal, there’s multiple scandals that are just flying at us,” she said.