You know, they didn't do much with Obama last year, other than the one Ben mentioned, and a couple of "Democratic Debate" segments. I think they were focusing on making fun of Hillary at the time. I also believe Fred Armison hasn't quite nailed Obama in a way that's, well, funny. After Will Ferrell left, they had similar problems with George W. Bush. They tried Chris Parnell, then the normally brilliant Darrell Hammond, then went with Will Forte for awhile, and finally settled on Jason Sudeikis. None of them have risen to the level of Ferrell's Bush or Hammond's Clinton.

(forgive a potential raft of incorrect spellings on the names above - I didn't have time to check)