After a long and contentious presidential election in 2016, it may come as a surprise to some voters that the 2018 midterm elections are just 18 months away and both parties are already preparing. The GOP has faced a difficult six months following the failure of its health care reform efforts and President Trump's historically low approval ratings , so it will likely spend the next year fighting to defend its majorities in both chambers while Democrats will campaign to pick up seats. Here's a quick summary of what's at stake.
What is a midterm election?
A midterm election is a national election held around the midpoint of a presidential term (two years after a presidential election.) All 435 seats in the U.S. House of Representatives are up for election, as are 33 or 34 seats in the U.S. Senate. Members of the House of Representatives are up for election more frequently than members of the U.S. Senate because they serve two-year terms rather than six-year terms. In addition, 34 of the 50 states elect their governors to four-year terms during midterm elections, while Vermont and New Hampshire elect governors to two-year terms in both midterm and presidential election years. Thus, 36 governors will be elected in 2018. Many states and localities also hold elections for state legislatures as well as mayors, city councils, secretaries of state, attorneys general, school boards, and a litany of other state and local elected positions.What patterns are evident in the outcomes of past midterm elections?
Midterm elections are almost always subject to a lower voter turnout than presidential elections. While about 50 to 60 percent of the electorate has generally turned out to vote for the president over the past 60 years, only about 40 percent of eligible voters participate in midterm elections. In 2014, voter turnout fell to a 70-year low of just 36.4 percent. Midterm election results are often interpreted as a referendum on the sitting president or incumbent majority party's performance. Often, the president's party loses seats in Congress, especially when their approval rating is low. Over the past 21 midterm elections, the president's party lost an average of 30 seats in the U.S. House of Representatives and 4 seats in the Senate. Presidents like Trump with an approval rating below 50 percent lose an average of 36 seats in the House. At this early juncture, Democrats have cited this historical pattern as a reason to be hopeful about gaining ground in Congress. However, past precedent is no guarantee of future results.Who will be running for reelection in the Senate?
Because a significant number of Democratic senators benefited from Barack Obama's reelection wave in 2012, those senators' six-year terms will expire in 2018. Thus, out of the 34 Senate terms that will be up for election, Democrats control 23. Independent senators Bernie Sanders of Vermont and Angus King of Maine, who caucus with the Democrats, will also face reelection. The Democratic party will start at a disadvantage because it will have to focus on defending a large number of seats rather than challenging Republicans. In addition, several Democratic senators from deep-red states that supported Trump in 2016 might be vulnerable to upset. Some of these races to watch will include those of Joe Manchin of West Virginia, Claire McCaskill of Missouri, Jon Tester of Montana, Joe Donnelly of Indiana, and Heidi Heitkamp of North Dakota. However, Democrats might have a few opportunities to target vulnerable or unpopular Republicans. Republican Dean Heller of Nevada is up for election in a state that swung to Hillary Clinton in 2016. Jeff Flake of Arizona has an approval rating of just 18 percent . Furthermore, Democratic Rep. Beto O'Rourke outraised Ted Cruz of Texas in the second quarter of 2017.What is the probability of an upset in the House of Representatives?
Unlike the Senate, every member of the House of Representatives will have to defend his or her seat in 2018. Under the traditional rules, it is logical to conclude that the likelihood of Republicans retaining their hold on the lower chamber is unlikely given Trump's low approval rating and the president's party's historical disadvantage. However, there are several factors that could complicate House races. First, partisan voting patterns have grown more distinct in recent years as Democrats and Republicans become more polarized. That could make it difficult for Democrats to convince Republican voters to support them. Secondly, Republicans control the great majority of state legislatures, which write congressional district maps. Political gerrymandering has created demographic conditions that favor Republicans in many districts, leading Republicans to control a quantity of House seats that outpaces their share of the general population. Thus, even though Democrats have a robust lead in "generic ballot" polls --which ask only which party a voter would support in a congressional election--there is no guarantee that this favorability could translate into House gains for them.Click here to watch Democrats sing "Na Na Hey Hey Kiss Him Goodbye" to Republicans on the House floor after the GOP passed a bill to repeal major parts of the Affordable Care Act. Click here for an informative Crash Course video on congressional elections. It covers frequency of elections in the Senate and House, typical characteristics of a candidate, and the motivating factors our congresspeople follow to get re-elected.
