But when Barrett became Trump’s third appointee in late 2020, giving the conservatives a six-vote majority, the longer-serving justices Clarence Thomas and Samuel Alito were “emboldened by the ascendant conservatism,” Biskupic writes. “Joined by the Trump appointees, they echoed the former president’s sense of aggrievement on culture war issues, from abortion rights to vaccine mandates. Their time had come.” (Much as with Trump voters, “grievance” is the obligatory reference when describing conservative justices. Biskupic claims that Alito, for one, sounds “perpetually aggrieved” and wears a “heavy cloak of grievance.” Perhaps the cloak fits under the robe.)

Biskupic, a CNN Supreme Court analyst and biographer of four current and past justices, dissects the personalities on the court. Justice Thomas, previously on the “ideological fringe” and often alone in his dissents, is now in the “vanguard” of the conservative supermajority: “Both he and Alito were only in their early 70s, but they felt a sense of urgency, as if their time were limited.” Justice Kavanaugh, meanwhile, comes off as painfully self-conscious, struggling to reconcile “his allegiance to conservative backers and his desire for acceptance among the legal elites who shunned him after his scandalous 2018 Senate hearings.” (Biskupic points out that Kavanaugh at times adds “appeasing passages” to his opinions and dissents, just to signal that he’s not a bad guy.)

So, when a chapter in “Nine Black Robes” is titled “The Triumvirate,” a reader might assume that it signals a discussion of the three Trump-appointed justices, or perhaps of some powerful new coalition on the court. Instead, it concerns a trio that has wielded power over the court from outside: Senator Mitch McConnell of Kentucky; Don McGahn, a White House counsel under Trump; and Leonard Leo, the conservative legal activist and a former vice president of the Federalist Society. “The three men understood the importance of the federal courts to a long-term policy agenda, from business interests to individual rights,” Biskupic writes, and they sought “jurists appointed ostensibly as neutral arbiters but who in reality held to their own ideologies.”

Each contributed to the same cause from his respective perch. McConnell blocked President Barack Obama’s nomination of Merrick Garland to the Supreme Court, a move he later called “the most consequential decision of my career.” McGahn shepherded Neil Gorsuch and Brett Kavanaugh onto the court and, anticipating an eventual promotion, positioned Amy Coney Barrett onto the Seventh Circuit Court of Appeals. Leo, skilled in vetting judicial nominees for ideological purity and reliability, worked with McGahn and others to assemble the list of potential Supreme Court nominees that Trump, in a brilliant effort to reassure Christian conservatives, released in May 2016. Indeed, it is a testament to Leo’s influence — and that of the Federalist Society — that he makes a cameo in the recent ProPublica report about Justice Thomas’s luxury vacations funded by a billionaire Republican donor. Inside the donor’s private lakeside resort in upstate New York there is a painting of Thomas relaxing with the donor and a few other guests. Sitting across from the justice? Leonard Leo.

In “The Brethren,” the stamp of approval of the American Bar Association is crucial for potential Supreme Court nominations (though Nixon does ask Blackmun if his daughters, in their 20s, were “hippie types”). In “Nine Black Robes,” it is the Federalist Society’s sign-off that matters most.