The State Similarity Rating attempts to quantify how similar states are to each other relative to other states. The index is a statistically-based way to measure this. 20% of the index is based on politics. 20% of a state’s politics score (4% of the overall State Similarity Rating) is allocated for the parties of their elected federal representatives. The following is an explanation on how they were calculated:
In the last five presidential elections, many states have always voted for the Republican candidate, while other states have always voted for the Democratic candidate. All the states on the West Coast vote for Democrats, except for Alaska. The same goes for most of the Northeastern states. The reverse is true for states in the South and many rural Western states with a low amount of racial diversity. These states always vote for Republicans. The Midwest is appropriately neither especially Democratic nor especially Republican heavy. Iowa and Ohio have voted three times for Republican candidates and two times for Democratic candidates in the past five elections. Florida is another state that Obama was able to win twice, unlike Joe Biden and Hillary Clinton.
Source: 270 to Win
There are two senators per state. The party of the state senators is highly correlated with which presidential candidate the state chooses, although there are exceptions. In recent times, West Virginia has been one of the easiest Republican victories for presidential candidates, however from 1958 to 2014, both senators from West Virginia were Democrats. Recently Montana also had an 8 year period of having two Democratic senators, despite always voting for Republican presidential candidates. Maine is the opposite. It has not had a Democratic senator since 1995, despite voting for the Democratic presidential candidate in every election since then.
Source: 270 to win
Since most states have more congressmen in the House of Representatives and their races are not state-wide, there is less correlation with the presidential election. Although Minnesota is one of the Democratic strongholds in the presidential race, the state’s representatives in Congress are closely split between Republicans and Democrats. Michigan is another Midwestern state with this characteristic. Texas is an example of a state where Democrats rarely win a state wide election, yet a large portion of their representatives are indeed Democrats.
Source: 270 to win
Republican Presidential Primary Election
Presidential primaries are harder to predict, since the candidates have less stark contrasts of political views between them. In general, the less conservative Republicans do better in Northern states, while more conservative candidates do better in the Southern states. Unlike the Democratic party primaries, there is less obvious contrast in voting between rural states with little diversity and more urbanized states with more diversity. This is because the Republican party is mostly White even in the most diverse states.
Democratic Presidential Primary Election
Most Democratic presidential primaries have had clear winners, where one candidate got a majority of votes in the vast majority of states. Two exceptions were Clinton vs. Obama and Clinton vs. Sanders. In the 2008 primary, Barack Obama tended to do better in states with more African Americans, but also states with high percentages of White progressives. Hillary Clinton did better in states with high populations of Latinos. In 2016, Bernie Sanders, did well in states with high percentages of White people, but failed to win many more diverse states.
Obviously there is no one clear way to determine how similar one state is to another. How would you quantify how similar one state is to another?
Please leave any thoughts in the comments section.