Internment camps in the US?

Still legal, because the SC decision that upheld the government’s right to hold Japanese Americans in camps has never been overturned.

From the decision:

It was because we could not reject the finding of the military authorities that it was impossible to bring about an immediate segregation of the disloyal from the loyal that we sustained the validity of the curfew order as applying to the whole group. In the instant case, temporary exclusion of the entire group was rested by the military on the same ground.

law.cornell.edu