I think the Dakotas are trending Democrat. Not enough to make a difference at Presidential elections for a long time if ever, but I think that that whole region (ND, SD, MN, IA, WI) are equalling out a bit more; the Dakotas will remain GOP friendly and I believe the upper midwest will remain vaguely DEM friendly for a few more years.
I disagree. The only state that even looks like it might be trending Democrat in Presidential politics in the Plains and Mountain West is Montana, but I'm not quite sure of that either.
Don't be fooled (as Shira often his about these things) by this election in 2004. Montana and South Dakota have historically strong anti-incumbent biases and nearly every incumbent that I can think of has always done worse in these two states the second time as opposed to the first (this includes, Reagan, Bush, Carter, Clinton, even Nixon I think).
As long as the ND and SD Dem senators bring in the farm pork for the two states, they'll be in fine shape unless they do what Daschle did these last 4 years.