But through the rest of 1935, Coughlin had trouble replicating his success on the World Court vote. His audience had never been larger, and his radio network had grown to twenty-eight stations covering every major city in the Midwest and Northeast (as a Catholic, Coughlin’s influence was always limited in the heavily Protestant South). He maintained his own full-time lobbyist in D.C. Nevertheless, Coughlin’s assaults on the Federal Reserve, the gold standard, and his support for a bonus bill for war veterans were all stymied through deft political maneuvering by Roosevelt and his allies on Capitol Hill.

Though Coughlin would repeatedly deny it, it seems clear that he had harbored some idea of the National Union as a potential third party in American politics from its inception. In typical apocalyptic fashion, he had been forecasting the demise of the two-party system for some time, telling Collier’s Magazine he thought both parties would disappear within a decade.

Seeking to fill this impending political vacuum, Coughlin embarked on a speaking tour that he hoped would recruit millions of new members for the National Union. Those who attended his thunderous rallies came away impressed by the passionate devotion of the crowd. And at first, Coughlin had some modest success. In 1936, candidates endorsed by the National Union won congressional primaries in several large states, including Michigan, Ohio, and New York.

Coughlin never believed that a third-party candidate could directly challenge Roosevelt. Yet he was convinced that the millions of voters organized under the National Union banner could weaken FDR and potentially put a Republican in the White House. As the 1936 election approached, Coughlin joined forces with the remnants of Long’s organization (the Louisiana senator had been murdered in the summer of 1935) and other third-party splinter groups to form the Union Party, which chose North Dakota Congressman William Lemke as its presidential candidate.

At the party’s convention in August, Coughlin stripped away whatever had been left of his relationship with Roosevelt, literally peeling off his vestments during a stem-winding speech that labeled FDR as the “great betrayer” and a “liar.” On the stump, Coughlin was even more graphic, telling supporters that “when an upstart dictator in the United States succeeds in making this a one-party form of government, when the ballot is useless, I shall have the courage to stand up and advocate the use of bullets.” The priest swore that if he could not deliver nine million votes for Lemke, he would retire from the radio.

He couldn’t. In fact, Lemke garnered less than a million votes, and not a single one of the Union Party’s congressional candidates won election. True to his word, Coughlin did briefly “retire” from the radio—only to allow his faithful flock to woo him back on the air early the next year.

For a while, he seemed disconsolate, saying that Roosevelt’s landslide win made him a de facto dictator and that conventional political resistance was useless. But although his influence was diminished, Coughlin was far from a spent force. When Roosevelt, in the midst of another economic slippage during his second term, attempted to reorganize the government bureaucracy, the priest regained his old form, blasting the legislation as a “dictator bill” and urging his listeners to telegram Congress.

The response was so overwhelming the wire services had to shut down all other traffic to handle the volume. The reform bill flopped. And though others opposed the legislation, FDR acknowledged that “the gentleman from near Detroit” was primarily responsible for its demise. “Demagoguery and stupidity,” the president wrote to an aide after the vote, “are the natural enemies of democracy.”

The final act of Coughlin’s conflict with Roosevelt hinged on America’s looming involvement in World War II. From the beginning, his repeated lambasting of “international bankers,” “money lenders in the temple,” and his harping on the supposed prominence of Jews in communist intrigues had generated charges of anti-Semitism. With his alienation from the New Deal and the threat of war in Europe, Coughlin’s rants took on a darker tone. His weekly newspaper, Social Justice, serialized The Protocols of the Elders of Zion, a paranoid fantasia about Jewish intrigues long since debunked by scholars. His speeches began to draw comparisons to Adolf Hitler’s—and in one instance, his newspaper appeared to reprint remarks made in Berlin by Joseph Goebbels without identifying their origin. Coughlin indignantly denied the charges of anti-Semitism, even as critics began to refer to his church as the “Shrine of the Little Führer.”

Coughlin’s reputation was further damaged when he announced a successor to the National Union called the Christian Front. The group quickly developed a reputation for thuggery, brawling on the streets, and roughing up people they suspected of being Jewish. They also picketed those radio stations that were beginning to shun Coughlin’s broadcasts.

Douglas McCollam is a contributing editor to CJR.