Does anyone have actual proof what religion this guy is?
Brennan went to Catholic grade school, high school, and college. He grew up in Northern NJ, and his parents were immigrants from Ireland.
None of the above means anything about what his current religious beliefs are. He sounds like a typical Jesuit educated leftist, who often mixes up religion and politics. (Pope Francis is another fine example.)
It isn’t surprising that someone who sees the ultimate aim of religion and politics as the same would be attracted to Communism or Islam.