I don't know how race and religion became interchangeable words.
I think they just like to use the term "racism" cuz it's the scariest to whomever it's directed at.
So the term just gets thrown around like candy from a pinata now.
It's all good tho. The term is starting to have about as much impact as the word "the".
2 a : a family, tribe, people, or nation belonging to the same stock b : a class or kind of people unified by shared interests, habits, or characteristics
The above is part of the definition of race from MERRIAM WEBSTER'S COLLIGIATE dictionary. I assume it would, broadly speaking, include religious groups.