Once upon a time, a Republican president distrustful of big government and enthralled with markets nominated a seemingly conservative man named Roberts to the Supreme Court. The president hoped and expected that long after he left the Oval Office, Justice Roberts would continue to do the work of his conservative movement. But Justice Roberts bitterly disappointed his erstwhile supporters, rejecting claims of states’ rights against the national government and defending the rights of minorities against the assertions of the national security state. A liberal fantasy? Hardly. The president was Herbert Hoover and the justice was Owen Roberts, who, in the...