What Is the Coattail Effect in Politics?

The coattail effect is a term in American politics used to describe the impact an extremely popular or unpopular candidate has on other candidates in the same election. A popular candidate can help sweep other Election Day hopefuls into office. Meanwhile, an unpopular candidate can have the opposite effect, dashing the hopes of those running for offices lower down on the ballot.

The term "coattail effect" in politics is derived from the loose material on a jacket that hangs below the waist. A candidate who wins an election because of another candidate's popularity is said to be "swept in on the coattails." Typically, the term "coattail effect" is used to describe a presidential nominee's impact on congressional and legislative races. The excitement of the election helps to increase voter turnout, and more voters may be inclined to vote a "straight party" ticket. 

Coattail Effect in 2016

In the 2016 presidential election, for example, the Republican establishment became increasingly concerned about its candidates for U.S. Senate and House when it became clear Donald Trump was a formidable candidate. Democrats, meantime, had their own polarizing candidate to worry about: Hillary Clinton. Her scandal-plagued political career failed to generate enthusiasm among the Democratic Party's progressive wing and left-leaning independents.

It could be said that both Trump and Clinton had coattail effects on the 2016 congressional and legislative elections. The surprising surge for Trump among working-class white voters — men and women alike — who fled the Democratic Party because of his promise to renegotiate trade deals and levy stiff tariffs against other countries helped elevate Republicans. The GOP emerged from the election in control of both the U.S. House and Senate, as well as dozens of legislative chambers and governor's mansions across the U.S.

House Speaker Paul Ryan credited Trump with helping the Republicans secure majorities in both the House and Senate. "The House majority is bigger than expected, we won more seats than anyone expected, and much of that is thanks to Donald Trump...Donald Trump provided the kind of coattails that got a lot of people over the finish line so that we could maintain our strong House and Senate majorities. Now we have important work to do," Ryan said after the November 2016 election.

Riding Coattails

A strong coattail effect often results in a wave election, when one major political party wins substantially more races than the other. The opposite usually happens two years later, when the president's party loses seats in Congress.

Another example of a coattail effect is the 2008 election of Democrat Barack Obama and his party's pickup of 21 seats in the House that year. Republican George W. Bush, at the time, was one of the most unpopular presidents in modern history. This was largely due to his decision to invade Iraq in what became an increasingly unpopular war by the end of his second term. Obama energized Democrats to vote.

"His coattails in 2008 were short in a quantitative sense. But he was able to enliven the Democratic base, attract large numbers of young and independent voters, and help to increase the party's registration totals in a way that boosted Democratic candidates up and down the ticket," wrote political analyst Rhodes Cook.

Source

Cook, Rhodes. "Obama and the Redefinition of Presidential Coattails." Rasmussen Reports, April 17, 2009.

Kelly, Erin. "House Speaker Paul Ryan says Trump saved GOP majority in House, Senate." USA Today, November 9, 2016.