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This post is being made available exclusively to paid subscribers like yourself. Thank you for making The Downballot possible. House race polling also points to a big blue wave Our new "named congressional ballot" aligns with other metrics predicting Democratic dominance Daniel Donner Oct 12 ∙ A recent Democratic poll of a House race in Ohio featured a remarkable finding. In the 15th District around Columbus, represented by Republican Mike Carey, the survey found Democratic challenger Don Leonard leading by a 46-45 margin. What made the result so noteworthy is that Carey’s district voted for Donald Trump over Kamala Harris by a comfortable 10-point spread in 2024. If that poll is indeed accurate, it not only means Leonard could win but also that he’s doing 11 points better than you’d expect given the outcome of the most recent presidential election. A political environment where Democrats are overperforming to this degree would be a very strong one indeed. But this is just one poll of one race. Alone, it can’t tell us anything about the broader state of the November midterms and whether Democrats do in fact have a mighty wind at their backs. But what if we look at all the available House polling and compare it to the Trump-Harris numbers for each district? Thanks to a database assembled by FiftyPlusOne, as well as The Downballot’s calculations of the 2024 presidential results for all 435 congressional districts, we can do exactly that. And when we do, we find that in polls in September of this year, Democrats overall are in fact doing as well as that Ohio survey implies. Compared to the presidential baselines, Democrats outperformed by an average of 11 points across 57 different polls last month. We call this the “named congressional ballot,” a cousin of the more familiar generic congressional ballot. In early July, FiftyPlusOne performed a similar analysis, finding Democrats polling ahead of their benchmarks in congressional races by 7 points on average. But we can now extend this analysis much further, because our colleagues at FiftyPlusOne don’t just have data on recent polls. Their catalog stretches back decades. That allows us to calculate the named congressional ballot for prior elections reaching back to 1998. And most importantly of all, these “back tests” let us see whether this approach offers any predictive value. It does—when it’s evaluated in conjunction with other metrics. These indicators all point toward a Democratic landslide that’s on track to eclipse even the “blue wave” of 2018. Why the “named congressional ballot” is valuable For our calculations of the named congressional ballot for all prior years, we included all House polls where the midline of the polling window fell between Oct. 1 and the election.¹ That choice of dates involves a tradeoff: An earlier cutoff would allow us to examine more data, but it would be more likely to pull in polls that weren’t reflective of the political environment as it stood on Election Day. The graph above shows that the named congressional ballot has, in recent years, been too optimistic for Democrats. However, in elections before 2010, its track record is better than the generic congressional ballot. This may be related to recent trends in educational polarization (which may be contributing to overestimates of Democratic performance based on special elections as well) if better-informed voters are more likely to make a choice in a named poll for their congressional election. But there are three years when the named and generic congressional ballot numbers converge. In 2004, 2012, and 2018, the two measures were only about 1 point apart. What’s more, in all three of these years, the actual House popular vote was pretty close to the generic and named polls, and was in fact spot-on in both 2012 and 2018. We can therefore say that when both of these measures show a similar value, it may mean that they will be close to the final value. Most importantly, they are converging again this year, with the two measures only 1.4 points apart based on September values. Adding it all up But what if the polls are wrong? Let’s add in the two other measures that we know have a pretty good track record by themselves: special elections and the difference in national primary turnout between the two parties. This chart shows midterm years only, and covers two election cycles for which we lack named ballot data. Notably, there are four years when all available measures are in rough agreement—not as close as 1 point, but more like five points. In these cases (1990, 2002, 2018, and 2022), the House popular vote wound up right in the middle of that narrow range three out of four times. And this year, we’re seeing a fairly narrow range again so far. Not only that, but the congressional ballot measures have both been moving higher for Democrats over the past few months, tightening the range. In some years, however, we’ve seen a fairly wide divergence between these measures. Sometimes one particular metric lies very far from the rest (the national primary in 2006, for example, or special elections in 1998), but usually that hasn’t been the case. So what can we do? The answer is simple: average out all of the measures. This brings us back to the figure that opened this post, repeated here for convenience. Averaging all four, it turns out, works remarkably well, as shown by how close the yellow and blue dots are in the graph above. In fact, in five of the last nine cycles, the multi-metric average and the House popular vote differed by less than 1 point. And in 2018, during the last blue wave, you can’t even see two distinct dots because the results were virtually identical. That year, these four indicators converged on a reading of 8.5. The actual House vote favored Democrats by 8.6 points. As a result, they flipped 40 seats and reclaimed the chamber. Based on this graph, we would expect Democrats to win the House popular vote—if the election were held today—by no less than 7 points, with a nominal prediction margin of 11 points, as shown by the blue dot in the upper right corner. However, we’ll be watching closely to see how the congressional ballot numbers change over the coming month, and how they affect this prediction. The big picture: What things look like right now Two of our four indicators—those relying on special elections and primary turnout—are already in the books. These are based on actual votes cast. About 40-50% of Americans who vote in November vote in the primaries. The other two indicators, meanwhile, are still “warming up”; they are based on polls. One is an average of polls for individual House races from Oct. 1 to Election Day; the other is an average of generic congressional ballot polls from the final week or so before Election Day. Their warm-up performance is usually—but not always—pretty close to their final values. Sometimes all four indicators are very different—indeed, sometimes they don’t even all favor the same party. But if we average their performance, we will still have a good indicator of what the voters will do in the end. Sometimes all four indicators are very similar. When that happens, which is about half the time, the average has an even better chance of being accurate. So far this year, the indicators based on special elections and primaries are nearly identical, and the indicators based on polls are getting closer to those election-based metrics. All four point to a very strong political environment for Democrats—and one that’s even better than what we saw in 2018. 1 For 1998 and 2000, our cutoff was Oct. 15 due to a lack of earlier data. Thank you so much for being a paid subscriber to The Downballot! If you’d like to further support our work, you can donate on our ActBlue page.