Currently, forty-eight states allocate Electors on a winner-take-all basis. Only Maine and Nebraska have a distinctive allocation mechanism, and in both of these cases, the winner of the state’s popular vote receives two Electors (those representing the senators) and the remaining Electors are distributed according to the popular vote in each of the congressional districts. This paper focuses on the political implications — historical, current, and future — of the adoption of the Congressional district allocation procedure by all of the states. We begin by assessing the historical impact of an ex ante universal adoption of the Maine-Nebraska allocation rule by all fifty states during the post-World War II era. After estimating the effect of this institutional change on the outcome of each election, we identify those districts and states which would have been the “battleground” constituencies for each election. We then assess the number and location of each of the battleground areas. We are particularly interested in the geographic dispersion of battleground districts relative to battleground states. We present data on this dispersion for recent elections and discuss the electoral implications of this dispersion in the context of widespread use of the Congressional district allocation procedure.