Thanks for at least tackling it fairly. The Bill Frist hypothesis:
The Democratic Party -- yes, and I'd find it opposition politics as usual. If the Republican Party isn't making a big deal about Kennedy right now, then they have more restraint than I give them credit for OR it's just not an inflammatory enough remark for them to risk looking like whiny jerks. The Bill Clinton affairs from Whitewhater thru the Impeachment don't exactly paint the party as the caricature of maturity and restraint, and to some degree it's productive to have an opposition party criticizing those in power.
The NAACP -- not sure; I'd have to know what their history with Kennedy is better. I know he's not universally loved by minority activists groups by any means.
The Media -- ONLY if either of the first two led the charge. The media hasn't said much about Bill Frist since he got nominated, and they've had plenty of opporutnity to slam the job he's done. He just has flown below the radar for the most part, unlike say Newt Gingrich who invited a lot of the high profile he had as Speaker.