There is in point of fact a very biblical reason that disqualifies Obama from being the Antichrist.
Daniel 9:26 specifically states that "the prince who is to come" i.e., the Antichrist will be a direct descendent of the people who destroyed Jerusalem and the temple in Jerusalem:
“Then after the sixty-two weeks the Messiah will be cut off and have nothing, and the people of the prince who is to come will destroy the city and the sanctuary. And its end will come with a flood; even to the end there will be war; desolations are determined." (Daniel 9:26)
Both Jerusalem and the sanctuary (the temple) were destroyed by the Roman army led by Titus of Rome in A.D. 70. The last time I checked, Obama has been referred to as a citizen of Kenya, and possibly, IF a legit birth certificate can be produced (highly unlikely) he may be a citizen of the United States. In either case, neither qualifies him as a citizen of Rome or of the revived ROMAN empire which Holy Scripture says is to come.
Given the above, there are indeed biblical grounds for disqualifying Obamessiah as the Antichrist. That said, there is no doubt in my mind that Obama is AN antichrist who exhibits the spirit OF Antichrist.