Whether Garcia has "MS13" tattooed on his hand or not (and he does not), he still has a right to due process, and he's not getting it.
Whether the many other men in that concentration camp are MS13 members or not (and many of them are not), they all still have a right to due process, and they're not getting it.
TFG is spreading lies about an issue that wouldn't even excuse his behavior, to move the point of contention away from rigidly defined principles like facts and laws, and toward more malleable affairs like the mood of mobs.