An Investigation into the Correlation between a Presidents Approval Rating and the Performance of His Party in the Midterm Elections

TL;DR

This study analyzes how a president's approval rating impacts the number of congressional seats won or lost in midterm elections, revealing a significant correlation and providing predictive models based on approval ratings.

Contribution

It introduces a statistically significant linear model linking presidential approval ratings to congressional seat changes, with improved accuracy for ratings above 50%.

Findings

Approval rating significantly predicts seat gains or losses.

A linear model explains 20% more variance for ratings over 50%.

Predicted seat loss for Obama in 2014 was accurate.

Abstract

Over the years, American politics have become increasingly polarized. In the current political landscape, a president cannot easily collaborate with the opposite party and pass legislature. Ideologies between parties have drifted apart to the point that one party generally stonewalls any legislature proposed by the other party. Because of this political landscape, it is paramount for a president to have a majority of his party in Congress. Political parties invest a great deal of time and effort into making sure that first their Presidential candidate wins and is popular, and then their congressional candidates win seats in Congress. In this study, the effect of the former on the latter was investigated - how the approval rating of the president influences the number of seats won or lost in Congress during the midterm elections. The data used was collected from Gallup. An analysis of the data yielded the statistically significant linear model y = -107.423+1.594x, where x is the approval rating of the president and y is the number of Congressional seats won or lost by the party of the president. Further analysis yielded a 20 percent more statistically useful model for approval ratings greater than 50 percent: y = -275.461+4.37551x. As of the eve of the 2014 Midterms, President Barrack Obama had an approval rating of 44 percent. Using the originally derived linear model, it can be said with 95 percent confidence that the Democratic Party will lose between 27 and 48 seats in Congress, rounded to the nearest whole seat. This prediction has since been proven correct.