The truth about this Carson thing is this: Most likely Obama didn't give it much thought.
Carson came off as just another hanger-on seeking the spotlight and testing out the political waters. It's become clear that he's seeking to run for office and he's testing the reaction. As usual, the rightwingers are clinging to this -- they are in desperate need of diversity in the Repub. party and they're hoping that Carson is the "Next Big Thing" for them.
Being rude, disrespectful and speaking inappropriately may have some appeal but I'm guessing that if Carson showed poor judgment in this venue with his boorish choice of words, that he's not a very good prospect for the Repubs going forward