This map uses election data from 1856 to 2012 to show the most Republican and Democratic states over US presidential election history. This map was NOT created by adding all the total votes for each party in each state and comparing them, as that would put more weight on more recent elections. Instead, an average was taken of the two-party share of the vote in each state, after eliminating votes for third-party candidates. So, if a state voted 40% republican, 45% republican, and 50% republican in three elections, it would average 45% republican, even if significantly more votes were cast in one election than the others.
The data starts in 1856 because that’s when the Republican party first debuted in a presidential election.
A few observations based on this map:
– A lot of the presidential geography we take for granted is very recent. The South is a mostly Republican area today, but was the “Solid South” for the Democrats for over a century. Even after the battle over Civil Rights switched the South to the Republicans, Democratic presidential candidates could compete in that region. Carter swept most of the South in 1976, and in 1980 it was one of his stronger regions in a landslide loss. Bill Clinton was able to win several southern states in both 1992 and 1996. And even Obama has won a few southern states in both 2008 and 2012. If we balance 100 years of solidly Democratic voting with 50 years of a slight Republican lean, we can see why the South comes out in this map as a Democratic region.
-Likewise, a state like Vermont that we think of as solidly Democratic is really a very recent addition to the Democratic coalition. The state didn’t switch sides until 1992, before that it was usually a solidly Republican state with Democrats only winning it in landslides such as 1964. Because of this long history as a Republican state, it is second only to Kansas in average Republican vote.
-If we were to use the current electoral college, and assign states based on which party got a higher share of the two-party vote from 1856 to 2012, the Democrats would win in a very close election, 296 electoral votes to 242.
-Looking at Republican states, their most consistent stronghold has been the Great Plains and the Western Mountain states:
|State||Republican Share of the Two Party Vote, 1856-2012|
|District of Columbia||12.89%|
Looking at the results above, the “swingiest” state has been New Jersey, where Republicans have won an average of 50.13% of the two-party vote since 1856.