Many of us call this the Foley phenomenon. Tom Foley was our Congressman for years - like 25 or 30 - but once he became Speaker of the House, he became a 'national' figure and no longer represented his constituents. He was carrying the water for Clinton which infuriated people further. We finally found a good candidate, George Nethercutt, and with a concerted grass roots effort (and it wasn't easy by any means) we managed to defeat the Speaker of the House. Everyone said it couldn't be done but we did it.
It can happen in South Dakota too. Once Democrats become 'national' figures they have to tow the party line, which means adhering to the NE liberals that control the party. This doesn't always bode well with folks back home. And all that nonsense about farm subsidies is silly. Everyone knows that no matter who they send to DC is going to support the farm subsidies, regardless of party affiliation.
I'd say it's time for the SD GOP to start finding a good candidate to go against Daschle in 2004.