Explaining electoral change in the 2018 US midterm elections: The three components of electoral mandates

Abstract

Why did the American electorate elect a solid majority of Republicans to the House in 2016 and then 2 years later replace it with a solid majority of Democrats? This article revives the idea of an electoral mandate and applies it to the 2016 and 2018 elections. It proposes a trinity of partisan attitudes serving as the components of electoral mandates: Performance, values, and leadership. The election of President Trump in 2016 depended on a mix of performance evaluations (a weak economy) favoring the Republicans and leadership evaluations (Trump's behavior difficulties) muted by value considerations (conservative anger at being unrepresented and the necessity of a choice between Trump and Clinton). These offsetting partisan attitudes made the election close enough that a small number of votes in key states decided the electoral vote outcome. In 2018, performance evaluations again favored Republicans, but now because they presided over a stronger economy. Evaluations of Trump's leadership remained negative. The interaction of values with these leadership assessments now favored Democrats. As the out-party, polarized liberals were motivated by anti-Trump anger. Never-Trump conservatives who had drifted back to vote Republican at the end of the 2016 campaign did not feel that same pressure without the presidency being at stake. About two-thirds of voters in 2018 said their vote was about Trump. Republicans lost to Democrats among these voters by 16 percentage points. Republicans delivered on their 2016 mandate to boost the economy, but had failed to provide leadership that many Americans could feel comfortable with.