The rational calculus of voting, first truly elaborated by Downs and forming the basis basically all research on voting behavior since, essentially places limits on an individual’s incentive to vote. For politicians a key theorem emerging from this calculus regards the “median voter”. The Median Voter Theorem argues that voters have an incentive to vote for their “true preference”. Thereby, voters will cast their vote for the candidate which presents policies closest, along a continuum, to this true preference. As a result, politicians must appeal to the center of this continuum in order to place their policies as close to the maximum number of voters as possible. But it has been suggested that this adage may no longer apply.
Political polarization in the United States is at an all-time high. Congress is more polarized than ever. The American public is more polarized than ever, and more ideologically distinct. Candidates for political office are more polarized than ever. The political center is shrinking. The incentive to appeal to the center thereby shrinks.
Furthermore, most important issues vary across the aisle. In many ways candidates cannot appeal to so-called “swing voters” because the votes are so dissimilar. So when Republicans constantly appeal to Donald Trump to pivot to the general it may be unnecessary, and impossible.