When it comes to U.S. presidential elections, analysts rightly focus on the Electoral College. After all, this is the system, rather than the popular vote, that determines the winner. But I think there are interesting trends in the popular vote that can be easy to miss if we just look at which states are colored red and blue in the maps we see every four years.
For a moment, let’s focus our attention on raw vote margins. In the 2016 race, Democratic candidate Hillary Clinton received roughly 2.9 million more votes than Republican candidate Donald Trump. This was a smaller margin than the approximate 5 million vote lead Barack Obama achieved over Mitt Romney in 2012. So we have a 2.1 million shift in the popular vote towards the Republicans that we have to account for between 2012 and 2016. Where did these votes come from?
Looking at the map above, we see lots of light shades of red. Mr. Trump was able to improve on Mr. Romney’s 2012 vote margin in many states across the country, but made particular headway in the Midwest. The three darkest shades of red on the map are Ohio, Michigan, and Pennsylvania. The Republicans improved their vote margins by 613,000, 450,000, and 354,000 respectively in these three states. Crucially for the Electoral College, they flipped from Democratic victories in 2012 to Republican victories in 2016.
Other states also shifted to the right in 2016, but received less attention because the winning party did not change and thus their movement had no effect on the Electoral College. Going down the list to the next three largest shifts towards the Republicans, we have Missouri, Indiana, and New York. Each of these states swung roughly 250,000 votes towards the Republican candidate for a combined approximate 750,000 vote swing. We don’t really think about states like New York at the presidential election level, but safe blue or red states can still have a large effect on the popular vote.
Another solidly blue state in the 2016 election that had a huge effect on the popular vote was California. As we can see by its dark blue shade on the map above, Mrs. Clinton actually improved on Mr. Obama’s 2012 margin in California by roughly 1.3 million votes. In fact, she won the state over Mr. Tump by about 4.5 million votes, more than her 2.9 million popular vote victory overall! Unfortunately for Democrats, this additional vote margin in California did not have any effect on the Electoral College vote.
Two other large swings towards the Democrats in 2016 were in Texas and Utah, where Mrs. Clinton improved on Mr. Obama’s 2012 margin by 455,000 and 284,000 votes respectively. Neither of these shifts changed either state from red to blue though.
For reference, here are tables of the top 10 states that shifted to the right and the top 10 states that shifted to the left, in terms of raw vote margin, from 2012 to 2016. Data for these charts, and the map above, came from the MIT Elections Lab.