There was definitely flack when black characters began to show up in the 1960s–at least partially due to the fact that the Black Panther Party came to prominence a short while after T’Challa’s introduction, which made it hard to separate the character from that particular brand of political activism. Catholic super heroes didn’t really present any difficulties, although I seem to recall the 700 Club at one point having an issue with a panel of Nightcrawler in church, but that was as much about them taking an image out of context to serve an agenda as anything.