“He was a lifelong anti-communist and was the man who took admitted Soviet spy Whitaker Chambers to the White House to see A.A. Abele in a quest to warn FDR about Soviet penetration there”.
What was FDR’s reaction? My guess is that he shrugged it off.
Basically the information (reportedly) never got to FDR. Remember, his two top aides were communists/sympathizers, Laughlin Currie (definitely Soviet operative) and Harry Hopkins (knowledgeable scholars are somewhat split as to whether Hopkins was a NKVD or GRU operative or just very pro-Soviet Union. More and more it looks like he was a Soviet asset/operative).
Hopkins’ assistant David Niles was reviewed in the Venona intercepts to have been “a contact of the KGB”. (see “Stalin’s Secret Agents: The Subversion of Roosevelt’s Government”, M. Stanton Evans and Herbert Romerstein, Threshold Editions, A Division of Simon & Schuster, 2012.
I trust both writers since I knew them for many decades and had long discussions about these issues.