Former White House counsel Don McGahn endured screaming matches with Donald Trump, badgering phone calls at home on his birthday and the president saying “some crazy shit” in order to advance the project closest to McGahn’s heart: packing the federal judiciary with activist conservative judges. McGahn’s lead role in developing the roster of judges used by Trump to remake the federal judiciary – Trump has elevated 201 judges and counting, including two supreme court justices – has long been known. But a new book by the New York Times reporter Michael Schmidt reveals for the first time the trials that McGahn, a libertarian who saw extreme judges as the best way to limit the scope of government, underwent to take advantage of the “once-in-a-never-again” opportunity he had in the chaotic early days of the Trump White House. The book, Donald Trump v The United States: Inside the Struggle to Stop a President, a copy of which was obtained by the Guardian, hits bookstores next week. In the book Schmidt, who originally broke the news that McGahn had cooperated extensively with special counsel Robert Mueller in the investigation of the Trump campaign’s Russia ties, deepens the picture of that cooperation. “McGahn had turned into the Mueller team’s personal Forrest Gump,” Schmidt writes, “the guy with the front-row seat to all the awful history of the Trump administration he had never wanted to witness.” Schmidt’s book focuses on the roles McGahn and the former FBI director James Comey played in attempting to contain a president both men recognized as mercurial and potentially threatening to the country. Comey was fired by Trump in May 2017, leading to the appointment of Mueller, one of many dramatic developments in Trump’s first term that Schmidt was in the vanguard of reporting at the time. Schmidt recounts that episode and many others with new details, to dramatic effect, in the book. McGahn left the White House in October 2018, after the successful confirmation of the man McGahn personally picked as Trump’s second supreme court justice, Brett Kavanaugh. While not seeming to share Comey’s anguished concern for the independence of the judiciary and the balance of powers under Trump, McGahn – a campaign law expert – had plenty of personal frustration with Trump, whom he referred to as “Kong” or “King Kong” or “fucking Kong”, after the hostile movie gorilla, Schmidt reports. The Mueller report previously documented McGahn’s run-ins with his boss. One of the key descriptions of potential obstruction of justice by Trump in the report describes Trump calling McGahn at home and instructing McGahn to put in motion Mueller’s firing, an instruction McGahn ignored apart from relaying it to his personal lawyer. But Schmidt reveals the previously unknown extent to which McGahn cooperated with Mueller, turning over “nearly a thousand pages of handwritten White House notes” to the special counsel. The cooperation was so fruitful, Schmidt writes, that Mueller’s team tried to “run” McGahn, or recruit him to gather information in real time about what was happening inside the White House. No such arrangement was explicitly made. Much of the book expands on major scoops by Schmidt during the special counsel’s investigation, including the revelations that the then attorney general, Jeff Sessions, was looking for dirt on Comey; that Trump had moved to fire Mueller; and scenes such as Trump’s explosion upon learning that the deputy attorney general, Rod Rosenstein, had appointed Mueller as special counsel: “It’s your fucking fault!” Trump thundered at Sessions. On multiple occasions, Schmidt writes, McGahn prepared his resignation as White House counsel, whose role is to give the president legal advice as it relates to the office of the presidency. McGahn prepared a one-line resignation letter after the White House came under pressure to withdraw Trump’s first nomination to the US supreme court, Neil Gorsuch, whom McGahn also had personally picked, according to the book. “Nominating judges was why he had taken the job,” Schmidt writes. “He was told this was going to be his turf, entirely.” Later, after Trump called him at home on his birthday – twice – and told him to tell Rosenstein to fire Mueller, McGahn went so far as to clean out his office at the White House and prepare another letter. “I have a real fucking problem,” McGahn told his personal lawyer about Trump, according to Schmidt. “I don’t want to speak out of school, but he’s saying some crazy shit.” But the resignation letter was never sent. The greater project, for McGahn, of appointing judges, as well as slashing government regulations, held precedence. Schmidt writes: “McGahn knew that he would never have this power again.”