It was not just Republicans who felt that the fault laid with FDR.
Read this Bad Choice for an Antiwar Voice By Charles Krauthammer:
"Harry, what the hell are you doing campaigning for that crippled son-of-a-bitch that killed my son Joe?' [Joseph P.] Kennedy said, referring to his oldest son, who had died in the war. Kennedy went on, saying Roosevelt had caused the war. Truman, by his later account, stood all he could, then told Kennedy to keep quiet or he would throw him out the window." -- "Truman" by David McCullough, Page 328The angry man was Joseph P. Kennedy, whose son Joe had been killed in Germany. He was speaking to Harry, or Harry Truman who succeeded FDR.
Here is the book.
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