PoliticsMark Halperin's DaybookWhy the Democrats' $1 million South Dakota gambit is a smart investment.FacebookXLinkedInEmailLinkGiftFacebookXLinkedInEmailLinkGiftGift this articleContact us:Provide news feedback or report an errorConfidential tip?Send a tip to our reportersSite feedback:Take our SurveyNew WindowFacebookXLinkedInEmailLinkGiftBy Mark HalperinOctober 9, 2014 at 12:38 PM UTCUpdated on October 9, 2014 at 12:45 PM UTCBookmarkSaveLock This article is for subscribers only.All times Eastern.The Senate math, scenarios explored: