It is because they still think in terms of "party" and feel that Carson is "one of ours."
I am not sure that either of them will ever get past that thinking, it is embedded deep within them.
“I can’t tell you how disappointing it was to hear Rush & Levin going nuts over this Carson crap on Friday.”
Indeed. Carson is no friend of conservatives, and no friend of the GOP unless you count the GOPe.