Is South Dakota in play in 2008? Perhaps, perhaps. We'll need more polling data to tell for sure, but at this point, virtually every state in the nation has the potential to tip blue. It's one of those years.
Examining the polling data here, the numbers in South Dakota are still in McCain's favor, albeit only slightly. Turnout will be the key, more than ever. If the Democratic turnout is very high, then anything is possible. I would still be very (pleasantly) shocked if Obama won the state.
In terms of strategy, even a close race in a deeply red state will be a win for Obama. It would force McCain to spend precious hours and dollars to prop up those votes, at a time when one Bush state after another peels away and the chances for victory appear less and less likely. The Republicans have already written off a number of crucial states, and cannot afford to lose any more. For our side, this means more resources available elsewhere in the nation. Being able to raise $5 million a day has its benefits.
I'll be looking forward to the upcoming polling from South Dakota. Should be fun.
KELO/Argus Leader 10/13-15. Likely voters. MoE 3.5%
McCain (R) - 48
Obama (D) - 40