In reply to Tyler, Mikkel, Offwidth: Thanks chaps, very kind. Amusingly, I've just applied for a job at a research institute to cover US domestic politics and its intersection with foreign policy. Maybe I'll send the link to this thread as one of my references!
The video has obviously 'gone viral' with millions of viewers, but that's interesting as it's not that special. He isn't really rude to the president and his points didn't strike me as very different to many other mainstream Republicans either. I guess the only thing seems to be that traditionally this national prayer breakfast or whatever the event was, isn't political. The GOP is always looking for articulate black advocates though, which is why they end up with oddballs like Allen West and Herman Cain. Anyway, I think Marco Rubio is a far better speaker than this Dr Carson, and doesn't have much to worry about come the next round of GOP primaries!