Only yesterday he was the Messiah.
Whether that's an upgrade or a downgrade, I can't say, but this Senator Obama character sure is one versatile fellow nevertheless:
Barack Obama the Antichrist
Incidentally, there is no one "Antichrist" in the Bible. There are a couple of mentions of "antichrists" (plural) among the three Epistles of John,* which refer to "many antichrists," and define an antichrist as "he [sic] that denieth that Jesus is the Christ," which would include Mahatma Gandhi, Golda Meir, and several other notables.
E.g., John McCain meets an antichrist.
* Including this bit of circular reasoning: "Little children, it is the last time: and as ye have heard that an antichrist shall come, even now there are many antichrists, whereby we know that it is the last time."
Evidently it's been the "last time" for quite awhile now. Could be they were referring to the eventual heat death of the universe, or at least our Sun's becoming a red giant in another few billion years.
But I doubt Barack Obama can affect either of those circumstances much, in spite of his amazing and remarkable superpowers.