Wikipedia is not evidence, but . . .

I never much looked into the FDR concentration camps for Italians and Germans during WWII.  Most everybody knows of the FDR concentration camps for Japanese Americans and I have heard a lot of justification for it from different sides.  Well, more like different flavors of Leftists.  I suppose that the support was the usual boilerplate on their favorite National Socialist in the USA.  Anyway, the links above have some numbers to go with them, use it as you will.

In her well researched and documented book It Happened In Italy, Elizabeth Bettina documents how Jews were treated in Italy during the days of Il Duce.  Contrary to some accounts, she has documentation of concentration camps being set up well before the 1943 German invasion of Italy.  However, the personal accounts of the survivors are quite a bit sunnier than those of the Japanese who were rounded up by FDR and heavenly when contrasted against any concentration camp survivor under Hitler.

These differences are the basis for a section in Would You Like Borders With That Socialism? that compares the various National Socialist regimes that were at war with each other from the onset of the Spanish Civil War through the Cold War. A comparison between National Socialism and International Socialism is in the works for another section, but honestly, there is so little difference that it is hard to write very much on that.