Regent believing in something just because some believe it, is not smart. You must think for yourself.
Regarding FDR, the evidence is overwhelming that he was a fool and a traitor. He did so many things that qualify for condemnation, but the interning American Japanese should qualify all by itself. To say nothing of his economic policies that impoverish millions and prolonged the Great Depression, his efforts to pack the SC, his numerous deceptive activities, his persistent lies regarding keeping us out of WWII while doing all he could instigate war, seeking reelection while dying during America's greatest war, consistently doing Stalin's bidding, etc...............................................................
I would suspect that FDR has been studied, analyzed, dissected and investigated as much any US president including Lincoln. There is little not known about him, or those about him, and it is all in the record, I even know what high school Harold Ickes attended. Yet with all that his known of his successes and his failures, historians and the people from his era still believe he was the greatest. I would suspect that any historian could make a good case, picking and choosing, that Lincoln was our worst president and people would accept it, I wouldn't. I think the historians are right on, FDR, Lincoln, Washington.
Interring the Japanese was a small factor in the scale of WWII and the Depression. The Court ruled it legal and America apologized and paid a few bucks. Would we do the same today under similar circumstances, I think we might. Look how we treated the Japanese before Pearl, or how some see Muslims at this time, or even the McCarthy period. Fear is a great motivator.
As for the prolonging of the Great Depression, do you have any idea of why FDR stopped the New Deal? There were no manuals, no textbooks on how to stop depressions, and there are still none today. FDR experimented and at times he was right and at times he was wrong, but he was trying.