YOU are the problem with America. This mentality is why MAGA controls our nation.
FDR didn't kill those people, his actions are not the same as Hitler's. Lincoln suspended Habeus Corpus, and the North operated POW camps that made Nazi Concentration camps look like a resort.
War is an ugly, monstrous thing, and decent people are forced to make immoral decisions. Some are going to be right and some are going to be wrong. We never know until it's over, and have to live with the consequences. You have no idea if interning those people means that a spy was bottled up, and couldn't sabotage the war effort toward the Japanese. The internment may have saved the war, but we'll never know.
What I do know, is that after the war, those people went free. They were NOT detained for life, they weren't executed. OTOH, Social Security has saved millions of lives, and employment reforms have saved millions of lives, and both have greatly improved the lives of EVERY American worker, every single day. That kind of fundamental improvements in the lives of every American cannot be simply dismissed because of one disagreeable action. ON BALANCE, FDR's good works far outweighed his worst mistake.
You are one of those shallow political thinkers who only see black & white, and are incapable of processing any nuance, which is unfortunately what politics is all about for many people. They want it to be easy, and morally indisputable, but the world is far more complicated than simple concepts or solutions. Your leaders are not going to be perfect saints, and if you insist that they are, then we are going to have nothing but MAGAs running our country in the future.