America's Fight Over World War II, 1939 - 1941 (2013)
FDR believed that Lindbergh was the main reason for the (in his opinion) hesitation for the U.S. to become more directly involved in aiding Great Britain against the Nazis. It was FDR's point-of-view that Lindbergh controlled the balance-of-power in the Isolationist Movement. Therefore, according to FDR's logic, if Lindbergh was the Lineal (Indispensable) Leader, and Lindbergh was taken out of the "Great Debate", then the Isolationist Movement would disappear as well. Dorothy Thompson, the most famous female journalist in the U.S. in 1941, went so far to compare Lindbergh's Isolationist followers to the Hitler Youth.
By the spring of 1941, FDR was convinced (like Ickes) that Lindbergh was a "Conscious Fascist". At the end of April, FDR appointed John Franklin Carter to be in charge of a secret organization . . . his mission was to collect information, from public opinion all the way to the actions of his enemies, and report only to the President.
For all intents-and-purposes, FDR called Charles Lindbergh a traitor to his nation.
Wendell Willkie did not support FDR's name-calling; he stated that Hitler should be the person that Americans despised. Lindbergh was uncharacteristically shaken by FDR's public attack, mostly due to the fact that the President questioned his loyalty to his nation.
Lindbergh's radio addresses became much more bitter, demagogic, and contentious. He specifically maligned FDR and other administration officials, claiming that they were undermining American Democracy. With FDR and Lindbergh setting the tone, the "Great Debate" to determine America's involvement in the War in Europe became even more vitriolic.
(Below: A portion of Lindbergh's America 1st speech at Des Moines on 11 September 1941; even if you listen for a few minutes, you can tell it was a controversial speech)
Lindbergh, more than ever, needed constant security when he appeared in public. J. Edgar Hoover (with FDR's blessing), had the FBI keep Lindbergh under very close surveillance . . . his phones had already been tapped for months. FDR asked FBI Director Hoover (pictured) to also investigate other prominent Isolationists, as well as major opponents of the Lend-Lease Act (those investigations presaged the FBI's investigational strategies during the Vietnam Era).
Geisel had already published two children's books as Dr. Seuss (the second was Horton Hatches an Egg), when he started working at PM. Geisel's cartoons constantly skewered Axis leaders and US Isolationists. Next to Hitler, Geisel's favorite target was Lindbergh, as you can see to the left. Geisel's symbol for Isolationism was the ostrich with its head in the sand; as a result of Geisel's attacks (and others), America First moderates left the committee, leaving the hard-core extreme right in charge of the "Firsters". Lindbergh, quite against his will, became the darling of the extremists in America First.
HUAC went after any "Communist" that it believed interfered with what they considered to be the "American Way", and Internationalists were on their list to investigate. The time between 1939 and 1941 was so divisive, even the ACLU
(American Civil Liberties Union) barred/expelled anyone that had political ties to groups that were associated with dictatorship in any nation.
The most divisive era in U.S. History during the 20th Century would reach its crescendo on 6 December, 1941, before Pearl Harbor not only rendered the "Great Debate" moot, but also blasted the "Great Debate" into historical oblivion . . .