Conor Lamb’s apparent upset victory in a Pennsylvania congressional district that Donald Trump had won by nearly 20 points has intensified talk of a Democratic wave in 2018. Lamb’s win is, in fact, evidence that Democrats have an excellent opportunity to recapture control of Congress this year. But in order to do so, it is critical that party decision makers understand just what a wave is—and what it isn’t.
In a nutshell, a wave happens when large numbers of one party’s base turn out to vote, swamping the ranks of their opponents. It is not a situation where a considerable amount of voters switch their party allegiances.
Many in the media, however, are already drawing the opposite conclusion about what Lamb’s win means—and what its implications are for November. The New York Times tweeted, for example, that the race was “the latest test of whether Democrats can make inroads with Trump voters.”
This interpretation may make for a good story, but it is bad analysis—and even worse political strategy. It stems from the fact that since Trump took office there has been a string of races in districts long seen as Republican strongholds where Democrats performed surprisingly well. In 2017, for example, Democrats won 14 of the 17 state legislative races in which party control flipped. The tempting story line is to conclude that voters in those districts are abandoning Trump and swinging their support to the Democrats. In mid-February, for example, Linda Belcher, a Democratic candidate in Kentucky, won a special election in a district that Trump had carried decisively Headlines trumpeted, “Democrats flipped a Kentucky state legislature seat in a district Trump won by 49 points.” CNN proclaimed, “A Democrat in Kentucky has won a state House seat in a district where President Trump won 72% of the vote in 2016.”
While technically accurate, such an analysis obscures the actual political trends that will likely determine the outcome of the 2018 midterm elections. To take an extreme example, imagine what would happen if every single person who voted for Trump skipped the upcoming midterm elections (perhaps there’s an Apprentice marathon on TV or something), and all of Hillary Clinton’s voters came out again to cast ballots. Obviously, every single Democratic candidate would win, even in districts overwhelmingly carried by Trump. This dynamic—Republicans staying home, while Democrats turning out to vote—is what accounts for Democratic success thus far. In the Pennsylvania race, for example, Saccone only got 53 percent of the vote that Trump got in 2016; Lamb won 80 percent of the vote that Hillary Clinton achieved that same year. Moreover, Lamb over-performed the most in blue Allegheny county—that’s where he clinched the election, not in Trump territory.