After thousands of articles and scores of books about Donald Trump’s mostly catastrophic presidency, it’s difficult for anyone to break dramatic new ground. But this new volume, with contributions from 18 American academics, is broader and deeper than all its predecessors, with essays covering everything from Militant Whiteness to the legacy of Trump’s Middle East policies, under the title Arms, Autocrats and Annexations.

The result is a great deal of information that is familiar to those who have already plowed through dozens of volumes, enlivened by a few new facts and a number of original insights.

One of the best essays, about the Republican party Trump inherited, is written by the book’s editor, Julian Zelizer. The Princeton historian reminds us that the “smashmouth partisanship” perfected by Trump actually began when Newt Gingrich snared the House speakership nearly 30 years ago. In 1992, Pat Buchanan’s speech to the Republic convention featured all of the gay-bashing Florida’s governor, Ron DeSantis, (and may other Republicans) have revived with so much gusto in 2022.

With major contributions from Fox News, Rush Limbaugh and the rest of the rightwing media machine, most of the GOP moved so far right it didn’t become Trump’s party because he “seized control” but rather because “he fit so perfectly” with it. Most Republicans were “all in” for Trump, from Mitt Romney, the ex-never Trumper who voted with his former nemesis more than 80% of the time, to “moderate” Chris Christie, who gave Trump an “A” four months after his four years of scorched-earth governance were over.

Nicole Hemmer, from Columbia, offers an excellent primer on the irresistible rise of rightwing media, reminding us that in the last year of the first George Bush presidency, Limbaugh was spending the night at the White House. By 2009, the shock jock “topped polls asking who led the Republican party”.

By the time Trump started his run for the presidency, in 2015, he had “grown far more powerful than the political media ecosystem that had boosted his rightwing bona fides”. This became clear after his dust-up with Megyn Kelly. Moderating a primary debate, the Fox anchor challenged his long history of sexist statements. Trump declared afterwards: “You could see there was blood coming out of her eyes, blood coming out of her wherever.”

The Fox News chief, Roger Ailes, “stayed silent”, Hemmer writes. Another executive, Bill Shine, “told on-air anchors not to come to Kelly’s defense”.

By the spring of 2016, Fox was becoming less important than Breitbart, an extreme-right website which researchers at Harvard and MIT declared the new anchor of a “rightwing media network”. It was Steve Bannon of Breitbart who “armed Trump with something like a cohesive political platform … built on anti-immigrant, anti-Black, anti-Muslim, and anti-liberal politics – the same agenda Breitbart.com was promoting”.

“Sure enough”, Trump’s Twitter feed “during the campaign linked to Breitbart more than any other news site”.

Eventually, just about everyone on the right became a Trump disciple. Glenn Beck compared him to Hitler in 2016. By 2018, Beck was wearing a red Make America Great Again hat, though he blamed the media’s “Trump Derangement Syndrome” for “forcing him to become a Trump supporter”. As a former rightwing radio host, Charlie Sykes, explained: “There’s really not a business model for conservative media to be anti-Trump.”

A Brown historian, Bathsheba Demuth, demonstrates that Trump was also a perfect fit for a party that endorsed a propaganda initiative of the American Petroleum Institute that portrayed environmental protection as “a dangerous slide toward communist authoritarianism”. Among loyal constituents were evangelicals, who either saw human dominion over nature as “a doctrinal requirement” or just thought the whole debate was irrelevant because of “Christ’s imminent resurrection”.

The most surprising fact in this chapter is that the fossil fuel industry was so sure Trump was a loser in 2016, it gave the bulk of its contributions to Hillary Clinton.

Margaret O’Mara, of the University of Washington, describes big tech’s key role in our national meltdown. She reminds us of a key, mostly forgotten moment 10 years ago, when “Google and Facebook successfully petitioned the Federal Election Commission for exemptions from disclaimer requirements” that required political ads to say who paid for them and who was responsible for their messages.

The companies argued the requirements would “undermine other, much larger parts of their businesses”. Disastrously, the FEC went along with that pathetic argument. After that, no one ever knew exactly where online attack ads were coming from.

O’Mara also recalls that Facebook provided the 2016 Trump campaign with “dedicated staff and resources” to help it purchase more ads on the platform. O’Mara mistakenly reports that the Clinton campaign received the same kind of largesse. Actually, in what may have been the campaign’s single worst decision, it refused Facebook’s offer to install staffers in Clinton’s Brooklyn headquarters.

Another chapter, by Daniel C Kurtzer of Princeton, analyses what Trump supporters consider their president’s greatest foreign policy achievement: the initiation of diplomatic relations between Israel and Bahrain, the United Arab Emirates, Sudan and Morocco.

A conservative journal summarized the accomplishment this way: “Washington is strengthening repression in Bahrain, underwriting aggression by UAE, sacrificing the Sahrawi people [of Western Sahara, to Morocco], undermining reform in Sudan and even abandoning justice for Americans harmed by Sudan. The administration calls this an ‘American first’ policy.”

The last chapter focuses on the two failed attempts to convict Trump in impeachment trials. Those outcomes may be Trump’s worst legacy of all. Gregory Downs, from the University of California, Davis, writes that the failures to convict “in the face of incontrovertible proof” may convince all Trump’s successors “that they have almost complete impunity as long as they retain the support of their base, no matter what the constitution says”.

• The Presidency of Donald Trump is published in the US by Princeton University Press