In the afterglow of his reelection triumph, Roosevelt pondered how to remove the remaining obstacles to New Deal reforms. He decided to target the Supreme Court. Conservative justices appointed by Republican presidents had invalidated eleven New Deal measures as unconstitutional interferences with free enterprise. Now, Social Security, the Wagner Act, the Securities and Exchange Commission, and other New Deal innovations were about to be considered by the justices.

To ensure that the Supreme Court did not dismantle the New Deal, Roosevelt proposed a court-packing plan that added one new justice for each existing judge who had served for ten years and was over the age of seventy. In effect, the proposed law would give Roosevelt the power to pack the Court with up to six New Dealers who could outvote the elderly, conservative, Republican justices.

But the president had not reckoned with Americans’ deeply rooted deference to the independent authority of the Supreme Court. More than two-thirds of Americans believed that the Court should be free from political interference. Even New Deal supporters were disturbed by the court-packing scheme. The suggestion that individuals over age seventy had diminished mental capacity offended many elderly members of Congress, which defeated Roosevelt’s plan in 1937.

Supreme Court justices still got the message. The four most conservative of the elderly justices—the “four horsemen of reaction,” according to one New Dealer—retired. Roosevelt eventually named eight justices to the Court—more than any other president—ultimately giving New Deal laws safe passage through the Court.