No Japanese-Americans were convicted of espionage or sabotage throughout the war (unlike German Americans), and the 442 is still the most highly decorated unit in U.S. Military history.
Who was really loyal was pretty fucking clear, and it wasn't that scumbag fdr.
Calling FDR a scumbag for interning Japanese in WWII is the same as calling America and what we refer to as "The Greatest Generation" as scumbags.
The action to intern the Japanese was overwhelmingly supported by the American population. They believed and many still believe that if not for the US Navel victories in the Pacific against the huge overwhelming force of the Japanese Navy, the US west coast would have experienced major attacks.
The guy you call a scumbag was the guy responsible for insisting, promoting and eventually developing and producing advanced aircraft carriers and attack aircraft that defeated the Japanese Navy, which would have been greatly advanced technologically if FDR did not have the knowledge of Navel warfare and the skill to advance the US Navy in a way that would shock the Japanese Navel commanders. The US Navy would have most surely been defeated in the Pacific if FDR's advancement had not been supported and made during his first two terms in office during the 1930's.
Most people are not knowledgeable or ignore an important fact about FDR. He served as Assistant Secretary of the Navy for seven years, 1913 to 1920, before during and after WWI. Before becoming a politician he spent years working with and coordinating military affairs and spending time with military commanders. He was in fact, a military expert with a military background.