The first wave of Obamacare cancellations has hit a group of Americans who are well-positioned to swing several critical Senate elections next November. “This voting bloc could have a decisive impact in close races in 2014,” according to a Nov. 11 memo from Resurgent Republic, a survey firm that tracks public opinion on GOP-related priorities. “Four of the nine most competitive states that Senate Democrats are defending have self-insured populations at or above the national average” of 5 percent, said the report. …