How important is it for polling organizations to include the correct proportions of self-identified Republicans and Democrats in their polls? The short answer is: Extremely.In this hyper-partisan age, the partisan ratio can not only determine the poll’s top-line results, but also shape the ensuing media interpretation of what it all “means.†That interpretation defines the expectations game, which, in turn, affects fundraising, voter enthusiasm, and turnout.According to a spate of recent polls conducted by Marist/NBC News, Democrats hold strong or even commanding leads in three key U.S. Senate races: Florida (up 4 points), Virginia (up 6), and Ohio (up...