The chaos that marked Donald Trump’s presidential campaign is a hallmark of his presidency. Decorum once associated with the Oval Office has been replaced by “modern presidential”, an amalgam of tantrums, tirades, and tweetstorms, all emanating from 1600 Pennsylvania Avenue or Trump-owned properties. This break with the past is every bit as much about substance as it is style.

Trump’s legal brush-back pitch hurled at the author Michael Wolff, his firing of FBI director James Comey and his taunts of Kim Jong-un, North Korea’s dictator, are not simply poses. They graphically reflect Trump’s understanding of his powers and the deference to which he believes his decisions and person are entitled.

David Frum’s Trumpocracy is an attempt by the former speechwriter for George W Bush – author of the term “axis of evil” – and never-Trump Republican to come to grips with this. He laments what he views as “the corruption of the American Republic” and painstakingly catalogs the threats he sees posed by Trump to America, liberal democracy and Europe.

Frum is disturbed by Trump’s nepotism and tropism toward kleptocracy, citing a legal ruling obtained by Trump that the White House was outside the scope of federal anti-nepotism laws. More broadly, Frum is alarmed by Trump “disabling” the “federal government’s inhibition against corruption” and his disdain for the notion that the law should be insulated from politics. To prove his point, Frum cites Trump’s expectation of personal loyalty from federal prosecutors and his public comments that the FBI director “really reports to the president”.

Frum is not sanguine about a return to old norms in a post-Trump America. He observes that “it took a lot of work by a lot of people over a long time to build even America’s highly imperfect standards of public integrity”. Like Rome, which was sacked in an afternoon, Frum adds, “undoing that work would be a far easier task”.

At the same time, Frum confronts the disconnect between white working class voters and America’s elites, and acknowledges that while it was Trump who lit the fuse, the powder that exploded on election night 2016 was all around: “Donald Trump did not create the vulnerabilities that he exploited. They awaited him.”

Frum rattles off the systemic stresses generated by globalization and immigration that led to Trump’s electoral college win. In that vein, Frum had already been skeptical about the benefits of immigration. As he writes here, “population is citizenry as well as a labor force … and when it grows slowly, it can less easily assimilate newcomers.”

Frum is mindful that the terms “Trump-voter” and Republican are not synonymous. To illustrate this point, he dissects in granular detail how Pennsylvanians reelected Pat Toomey, their incumbent Republican senator, while casting their lot for Trump, then diagrams the Toomey and Trump electoral coalitions. Although their voters overlapped, they were not identical. Class fissures were prevalent.

Yet it is over the very issues of class and the country’s red-blue divide that Frum appears to miss part of the picture. It’s not only about jobs, income, opioids or even race. It is also about the impact of America’s 21st-century wars, and who has done the actual fighting and dying.

The fact is that red state residents are over 20% more likely to join the military, while the denizens of blue America punch way above their weight when it comes to college. Even as Hillary Clinton won 2.86 million more votes, Trump won 60% of veterans.

Ironically, the George W Bush administration helped set the stage for Trump. There was a notable correlation between battlefield casualties and support for Trump. Those parts of the US that felt the carnage more as a reality than as an abstract swung Republican. According to Douglas L Kriner of Boston University and Francis X Shen of the University of Minnesota, “Wisconsin, Pennsylvania, and Michigan could very well have been winners for Clinton if their war casualties were lower.”

Frum’s book is a victim of timing, buffeted by the release of Wolff’s Fire and Fury and the passage of the tax bill. In addition to lambasting Trump for his authoritarian tendencies, Frum takes the president to task for a lack of accomplishments, for delivering “very little by way of an affirmative conservative agenda”.

Actually, since the book was put to bed, a lot has changed. Heading into 2018, the tax code has since been upended, Obamacare’s individual mandate is gone and the US recognizes Jerusalem as Israel’s capital. While the desirability of any of this is clearly subject to debate, each development is tangible and potentially lasting.

The author is on stronger ground when he examines Russia’s role on the global stage, the 2016 election and the intellectual moorings of Trumpism. Frum critically quotes a 2014 speech in which Steve Bannon offered more than a mere dollop of praise for Vladimir Putin, and for that period in American history where “freedoms” were “controlled at the local level”. As a coda, Bannon also described a June 2016 meeting at Trump Tower as “treasonous” and “unpatriotic”. And we know how that ended.

Frum is less than optimistic as he looks at the US, Europe and the future. Trumpocracy also struggles with how to actually connect with white working class voters, who may have comprised as much as 45% of 2016’s electorate and who are now the heart and soul of the Republican base. As the scholar Barrington Moore Jr. said more than a half-century ago, “No bourgeoisie, no democracy.” How all this plays out in the years ahead remains the open question. Frum, for one, is fearful, and understandably so.