If you take this argument that general, then I would say Islam is also one of the most popular religions on earth but well, very lowly reprecented in the US army (below 0.4 percent)

https://soldiersangels.org/the-diversity-of-our-service-memb...

History is why catholics are at 20%. Which is a significant force and a dangerous game to alienate them.

I pledge ignorance. Yeah, sorry should have looked that up before posting. I was always under the impression, North America tended towards other faiths, like Baptism or Mormon.