Midterm Election 2014: Why Tom Cotton defeated Mark Pryor

This post originally appeared on Slate.

Did Arkansas Senator Mark Pryor go down for the same reasons Blanche Lincoln did four years ago?

Here are some numbers to consider. In 2010 when Lincoln lost, 41 percent of voters said their vote was to express opposition to Barack Obama. Exit polls show that for Pryor, 40 percent of the voters cast their vote to express opposition to Barack Obama. Nationally, 41 percent of voters said they had a "positive" view of President Obama, but in Arkansas only 31 percent had a positive rating.

That's why Tom Cotton spent so much time talking about Barack Obama in this race. In one debate, Cotton mentioned Obama's name 74 times in 90 minutes. Feelings about the Affordable Care Act in Arkansas are also roughly the same as they were four years ago. In 2010, voters were asked "what should Congress do with new health care law" and 55 percent said repeal. Those voters overwhelmingly went for Lincoln's opponent John Boozman, 82 percent to 11 percent.

When voters were asked again this year "what should Congress do with new health care law," 55 percent said it should be repealed. Of those voters, only 18 percent voted for Pryor, while 80 percent voted for Cotton.