SD is not even a remotely "swing" state in Presidential elections. Not even McGovern carried the state he won 3 Senate contests in. Edwards didn't help carry NC in '04, and Gore didn't carry my state of TN in '00 (and barely helped in '92 or '96 where Perot deprived the Bush I and Dole the majority).
It was a joke. Like the thought of Tom Daschle running for POTUS.