Clarence Thomas has struck again.

To his impressive list of recent supreme court victories – abolishing the right to an abortion, eradicating affirmative action, undermining federal regulations, and more – the ultraconservative justice can now add thwarting the criminal prosecution of Donald Trump for hoarding classified documents.

On Monday, Judge Aileen Cannon astonished the judicial world by dismissing the case. She did so based on a widely discredited legal argument that the special counsel who brought the prosecution, Jack Smith, had been improperly appointed.

The argument, initially aired by the former US president’s lawyers, had received scant support in judicial circles, given that stretching back a quarter of a century it has been repeatedly rejected by the courts. But there was one jurist who encouraged Cannon to pursue such contrarian thinking: Thomas.

Two weeks before Cannon’s stunning dismissal, Thomas essentially prodded her into making the move. In a concurring opinion to Trump v US, the US supreme court ruling awarding the former president immunity over his “official acts” in the lead-up to the January 6 insurrection, the hard-right justice sketched a legal roadmap that Cannon then duly followed.