The GOP Is Gaining in the Generic Congressional Ballot. Does That Mean Anything?

For much of December and early January, Democrats held a double digit lead in the RealClearPolitics average for the generic ballot–a poll that basically asks a national sample of voters which party they intend to vote for in the upcoming congressional elections. Today, that advantage is down to eight points, and on Wednesday a Monmouth poll showed Democrats with a narrow two point advantage. While it’s important not jump to conclusions based on one poll, the message from all the polls is clear–the Democratic advantage in the generic ballot has fallen by several points.

So how happy should Republicans be about these improved numbers? And how worried should Democrats be?

It’s easy to give short, preliminary, semi-squishy answers to these questions (e.g. the GOP should be happy whenever numbers move their way, Democrats still have a real advantage, etc.), and it’s often important to get an initial read on new numbers before they’re swept away by the next news cycle.

But it’s also important to make sure that we have good mental models and don’t overreach or underreact to new data or poll numbers. That’s why I put together this short explainer on generic ballot polls that talks through how stable they are in the long term and the short term as well as how to interpret the polls we’ll see in the coming weeks.

The generic ballot is pretty stable

In general, congressional generic ballot polls are stable. I’m not the first analyst to point this out. Harry Enten did a great regression showing that early generic ballot poll averages were strongly correlated with the eventual House popular vote result, and Nate Cohn of the New York Times' Upshot vertical showed that the average of generic ballot polls almost a year before Election Day typically aren’t that far off the average near Election Day.