I am christian, but I know that is BS. The following may be considered "rational", christian idealists be warned
The MARK of the beast is the NUMBER of a man. The beast is a servant to a "man" (which could mean empire, or an idea of a man like the dahli lama or budda). There is no proof, but an inscription supposedly on a popes crown (Vicarious dei something, meaning "next to god") has the roman numeral equivilent of 666, ZOMG?!?!?!
Obama is liked (in my opinion) because he shows a sign for america to change. Im not saying he will be the best president, but the fact that he does show people that there is no longer the subtle racism that keeps african americans out of any type of power. Just my opinion.
The anti christ will be someone in an absolute power, the president is a link in the chain (the shiniest link, but still a link non-the-less). So unless we clone him hundreds of times, he can control anything absolutly from the oval office.