From the Pew Research Center: Democrats Made Gains From Multiple Sources in 2018 Midterm Victories

For our look at election results: An explanation of the 2018 national election. 

- Click here for the story.

- Click here for a similar study of the 2016 results. 

Compared with how Clinton fared in 2016, Democratic candidates for Congress in 2018 made gains from several sources. Among Americans who voted in both elections, Clinton’s 2016 voters supported Democrats in 2018 at a slightly higher rate than Trump’s voters supported Republican candidates. Slightly more of Clinton’s than Trump’s voters turned out to vote in 2018. In combination, party loyalty, defection and turnout differences among 2016 voters accounted for a little less than half of the Democratic gains over Clinton’s two-point margin.

Nonvoters in 2016 who turned out in 2018 voted heavily for Democratic candidates, accounting for about half of the Democratic gains. Additionally, a small share of the gains came from people who voted for third-party candidates in 2016; they favored Democratic candidates over Republican candidates in 2018 by a narrow margin.

Voting patterns in 2018 reflected a great deal of continuity with 2016, though Democratic candidates in 2018 did better among a few groups, notably men, young people and secular voters. Voting patterns among several other large groups changed less, including Black voters, voters ages 65 and older, Protestants, regular churchgoers and women.

Given their relatively lower turnout, midterm elections are not necessarily predictive of what will happen in the next presidential election, when many more American voters will take part.