There’s a version of the Jerusalem Cross used by Episcopalian service members, according to Wikipedia. I’m not American, so I don’t know the exact connotation of the symbol on that side of the pond, it could still be harmless. As an outsider, I’d associate it with the crusades (or the country of Georgia), but it doesn’t have to be intended that way.
Now, the fact that he’s a Trump appointee automatically makes him suspect, of course, but it’s less like “He has a Nazi tattoo, therefore Trump appointed a Nazi” and more “Trump appoints Nazis, therefore the tattoo is a Nazi tattoo”.
It’s good to learn from experiences, but it’s not good to assume that your experience is everyone’s experience.