LOL! All I have to say, is that (IMHO) he corrected and gave Obama a lesson in the Constitution & Obama is supposed to have taught Constitutional law.
Btw, to answer your original question (why?). The less well funded participants of these debates (everyone except Romney & Perry) are getting the free exposure necessary to climb in the polls and therefore open the way for contributions that they would ordinarily not get. I'm sure they fought for the 20+ debate format even if the "little guy" finds them tiresome and repetitive.