# The Arithmetic of Presidential Elections

In November of 2012, I remember watching Robin Meade on Headline News saying that the race between Obama and Romney was a statistical dead heat. Both were projected to get 47% of the popular vote. Meanwhile a guy named Nate Silver on his web site 538.com was predicting based on state-by-state data that Obama would win by a comfortable margin and he did.

2012    Obama            332      Romney          206

2016    H. Clinton       227      Trump             304      Other   7

2020    Biden               306      Trump             232

My question here: is what will happen in 2024?

By now it is widely recognized that there are Red States, Blue States and Swing States. To identify these we gathered data by looking at the Wikipedia articles on the 2012, 2016, and 2020 Presidential Elections, where it can be downloaded into a spreadsheet. Rather than use our “knowledge of politics” to classify the states, we declared a state RED if it had gone Republican in all three elections, BLUE if it had gone Republican in all three elections, and SWING otherwise.

Cleaning the Data

Dealing with real data is annoying. One immediate headache is that in Maine and Nebraska two electoral votes are decided by the voters of the state as a whole, and the others are determined by votes in the various congressional districts. This is handled differently in the three data sets. Since ME-1, ME-2, NE-1, NE-2, and NE-3 were consistently used for the districts, we made the brilliant decision to use ME-0 and NE-0 for the statewide electoral votes.

The New and North states were also a problem. In one data set they are alphabetized by their abbreviations: N.C., N.D., N.H., N.J., N.M., and N.Y. while in the other two the names are written out. Before I realized this, there were some very surprising patterns in the voting of New Yorkers. Finally when I thought I had found all of the differences I saw that in the 2020 Maryland was abbreviated Md. so it swapped places with Massachusetts, and in all three data sets West Virginia was written as W.Va and hence came before Washington (the state).

Our methodology

To create an ordering of the redness of states, we looked at the percentages of votes for Democrats minus the percentages of votes for Republicans, and ranked them by the sum of the numbers for the three elections. This produced the following classification:

Red States (170 Electoral Votes)

(Reddest first) NE-3, Wyo., W.Va., Oklahoma, Idaho, North Dakota, Utah, Kentucky, Arkansas, Alabama, South Dakota, Tenn., NE-0, Kansas, Louisiana, NE-1, Montana, Miss., Indiana, Missouri, Alaska, South Carolina, Texas

Blue States (215)

Minnesota, Colorado, ME-0, New Mexico, Oregon, New Jersey, Delaware, Washington, Illinois, Virginia, Conneticut, ME-1, Rhode Island, Vermont, New York, California, Mass., Maryland, Hawaii, D.C. (Bluest last) On the average 85% of people in DC voted Democratic in the last three years, but that may change this year

Swing states (153)

(almost red) Ohio, Georgia, Arizona, Iowa, ME-2, North Carolina, Florida, NE-2, Pennsylvania, Wisconsin, Nevada, Michigan, New Hampshire (almost blue)

Reality Check

According to Wikipedia “areas considered battlegrounds in the 2020 election were Arizona, Florida, Georgia, Iowa, Maine’s 2nd congressional district, Michigan, Minnesota, Nebraska’s 2nd congressional district, Nevada, New Hampshire, North Carolina, Ohio, Pennsylvania, Texas and Wisconsin.”