The Campaign Spot How Much of a Polling Cushion Will Herseth-Sandlin Need? By Jim Geraghty April 27, 2010 5:49 PM Share on Facebook Share on Twitter Share on Flipboard Share on WhatsApp Email this article At the end of last month, I asked whether Stephanie Herseth-Sandlin, the Democrat who represents all of South Dakota in the House, had reason to sweat. Rasmussen finds her leading all GOP competitors, but not by a ton: 4 to 15 percentage points.