Yes, Dewey, I do believe Roosevelt made such a speech, and it is the one Wolfgang found for you, though not exactly the same words as your grandfather used.Roosevelt was kidded a lot about this particular speech. Probably not to his face, but there were parodies of his speech going around. One of them was, "I have been in war, I have been in Elinor ...I prefer war!"
The U. S. was very pacifist prior to the attack on Pearl Harbor and had the American voters known that Roosevelt had every intention of the U. S. entering the conflict in Europe, it is doubtful that he would have been re-elected. At least that is how I understand it based on things I have read.
DougR