Liberal democracy is under attack from within. Institutional trust erodes. Fewer than one in six Americans believe democracy is working well, nearly half think democracy isn’t functioning properly, and 38% say democracy is simply doing meh. Atomization, bowling alone and nihilism have converged at the ballot box.

Republicans are hellbent on shoving the events of 6 January, when supporters of Donald Trump attacked the US Capitol, down a deep memory hole. GOP governors in Florida, Mississippi and Texas remain sanguine as Covid-19 dispatches children to intensive care. Seven months into his presidency, Joe Biden looks to some like Jimmy Carter redux, competence and judgment seriously doubted, allies strained and divided. FDR, he’s definitely not.

Into this morass parachutes Tom Nichols, with a meditation on the state of American democracy. Nichols grew up in a working-class home in Massachusetts and is now a professor at the US Naval War College and the Harvard Extension School. He is also a Never Trump conservative.

In his eighth book, Nichols is pessimistic.

“Decades of constant complaint,” he writes, “regularly aired in the midst of continual improvements in living standards, have finally taken their toll.”

The enemy, Nichols asserts, is “us”. Citizens of democracies, he writes, “must now live with the undeniable knowledge that they are capable of embracing illiberal movements and attacking their own liberties”.

As if to prove his point, Chuck Grassley, the ranking Republican on the Senate judiciary committee, recently made light of Trump’s attempts to have the Department of Justice subvert the election result. Even with Trump out of office, Senator Lindsay Graham continues to play first golf buddy, Renfield to Trump’s Count Dracula. A majority of congressional Republicans voted against certifying the 2020 election.

In 2016, Nichols urged conservatives to vote for Hillary Clinton because Trump was “too mentally unstable” – far from the “very stable genius” he would later claim to be.

In Our Own Worst Enemy, Nichols quotes Abraham Lincoln on how threats to American democracy always come from within: “If destruction be our lot, we must ourselves be its author and finisher.” Nichols sees the internet and the “revolution in communications” as the means by which we reached this dark point.

Public life has become ever more about dopamine hits, instant reaction and heightened animus. Our fellow citizens double as our enemies. Electronic proximity breeds contempt, not introspection. Social media and cable television provide a community for those who lack a three-dimensional version.

Nichols looks to ancient Greece for a reminder that nothing lasts forever. Admiringly, he quotes Pericles, the Athenian general and orator – but observes that Pericles was not around when his city state collapsed. He died two years earlier, behind “the besieged walls of Athens – from a plague”.

History can repeat itself.

In September 2016, writing in the Claremont Journal of Books under the pseudonym Publius Decius Mus, Michael Anton declared the contest between Trump and Clinton the “Flight 93 Election”: a reference to the plane that came down in Pennsylvania on 9/11 when passengers attacked their hijackers. Clinton, he argued, simply had to be stopped. First principles of conservatism could therefore be jettisoned.

“Charge the cockpit or you die,” Anton thundered. “You may die anyway … There are no guarantees.”

What, he asked, must be done “against a tidal wave of dysfunction, immorality and corruption?” To Anton, for the right, respect for “democratic and constitutional niceties” was ultimately a sucker’s game. Culture was stacked against them.

After a stint as a Rudy Giuliani speechwriter, and other stops along the way, Anton joined Trump’s national security council.

Later this year the Claremont Institute will honor Ron DeSantis. At a press conference earlier this month, the Florida governor asked: “Would I rather have 5,000 [Covid-19] cases among 20-year-olds or 500 cases among seniors? I would rather have the younger.”

A few weeks later, the Sunshine State is getting the worst of both worlds.

Simple decency, it seems, is for losers. Amid the last presidential campaign, comparisons between the US and the Weimar Republic were rife. The January insurrection was seen as our “Reichstag fire”. The attackers came from the right.

Nichols absorbs and abhors it all. Not surprisingly, he takes particular aim at the populist right, which he says has been the “main threat” to liberal democracy over the past two decades. That is subject to debate, which Nichols acknowledges. Regardless, he writes that the populist right “is a movement rooted in nostalgia and social revenge”.

As if to make Nichols’ point, Lauren Boebert, the hard-right, QAnon-adjacent Republican congresswoman from Colorado, recently trashed Biden for having left America’s friends in Afghanistan in the lurch – after voting last month against granting 8,000 immigration visas to Afghans who assisted the US military.

Other GOP diehards who opposed the legislation include Marjorie Taylor Greene, Mo Brooks and Paul Gosar. Greene and Gosar were charter members of the de facto white nationalist America First caucus. After a bomb threat on the Capitol this week, Brooks tweeted: “I understand citizenry anger directed at dictatorial socialism and its threat to liberty, freedom and the very fabric of American society.”

Considering what ails America, Nichols offers limited prescriptions. He supports bridging the gap between civilian and military life. The progeny of the coastal elites opt for Ivy League colleges over the service academies, reinstatement of the draft isn’t likely and notions of national service all too frequently amount to “little more” than a paid internship, he writes.

Concurrently, rightwing “Spartanism” breeds the unsustainable notion that “‘citizens’ and ‘soldiers’ are not the same people”.

Nichols urges America’s youth to spend a summer in uniform, exposed to military life and skills. Most won’t join the army, he thinks, but will come away with a better knowledge of the soldier’s life. Right now, he laments, “there is no longer any common experience related to national defense”.

Indeed. America has become one nation separated by a common language.

• Our Own Worst Enemy is published in the US by Oxford University Press