President Donald Trump’s personal lawyer Jay Sekulow said on Sunday that the U.S. Supreme Court may ultimately be called on to decide the scope of presidential pardon power.

If that happens, the justices will likely dust off one of the few cases in which the high court has ruled on the pardon power: the 1866 decision in Ex Parte Garland, involving one of the most prolific—and acerbic—advocates before the court: Augustus Garland.