An Unsettling New Theory: There Is No Swing Voter - POLITICO : And today her model tells her the Democrats are a near lock for the presidency in 2020, and are likely to gain House seats and have a decent shot at retaking the Senate. If she’s right, we are now in a post-economy, post-incumbency, post record-while-in-office era of politics. Her analysis, as Bitecofer puts it with characteristic immodesty, amounts to nothing less than “flipping giant paradigms of electoral theory upside down.” Her analysis, as Bitecofer puts it with characteristic immodesty, amounts to nothing less than “flipping giant paradigms of electoral theory upside down.” Bitecofer’s theory, when you boil it down, is that modern American elections are rarely shaped by voters changing their minds, but rather by shifts in who decides to vote in the first place. To her critics, she’s an extreme apostle of the old saw that “turnout explains everything,” taking a long victory lap after getting lucky one time. She see...