With less than 24 hours left until we freeze our model, we probably won’t see much more change in the peak forecast. Republicans have a 54 percent chance of winning the Senate and an 83 percent chance of winning the House, according to our Deluxe forecast. These numbers have been relatively stable in recent days. So let’s ask three big match prediction questions. These are not questions like “how much does abortion matter,” which I hope we do a good job of addressing elsewhere at FiveThirtyEight. Rather, they are questions that will inform our understanding of future elections from an analytical, polling, and predictive perspective.

Question 1: Will polls be systematically wrong?

We’ve covered this topic so often that you might think I have nothing more to say about it — but you’d be wrong! That’s partly because it really is the whole game, at least when it comes to which party retains control of the Senate. If Republicans beat the poll averages by, say, 3 percentage points, it would be highly unlikely for Democrats to save the Senate even if there is some variation from state to state. (Maybe they could hold on in Arizona and New Hampshire, but would be significant underdogs in Nevada, Georgia and Pennsylvania, where they must win two of three.) Similarly, if the Democrats won their polls by 3 points, the picture is very rosy for them. In that case, they would be favorites in Nevada, Georgia and Pennsylvania. Arizona and New Hampshire would likely be out of reach for Republicans. But conversely, Ohio, North Carolina and Wisconsin would be within reach for Democrats. The House would also be highly competitive in this case. Which type of voting error is most likely? If you’ve been following these election updates, you’ve probably noticed that I struggle back and forth between a “trust the process” mentality, where I take FiveThirtyEight’s model result as gospel, and a concern that the model may still be underestimating the likelihood of a pro-Democrat bias in polls, as we saw in 2016 and 2020.

How the 2 Parties Make Final Talks to Voters | FiveThirtyEight Politics

For what it’s worth, I’ve mostly landed on “trust the process.” My personal take on the race is pretty much aligned with the FiveThirtyEight Deluxe model. The polls could well be biased against Republicans again. The best reason to think so is probably ‘Nathan Redd’s’ argument that as the polls get harder, you should trust the fundamentals more. Typically, the president’s party has a tough midterm, especially when the president has a 42 percent approval rating and inflation is at 8.2 percent. But it’s not hard to imagine how the polls could be biased against Democrats. After 2016 and 2020, pollsters face more reputational risk from losing high again to Democrats than the other way around, and that could consciously or unconsciously influence the decisions they make on the sidelines or even which polls they release to the public. Additionally, the makeup of the polling media has changed significantly, with fewer “gold standard” polls and more quick and dirty ones that tend to show more favorable results for Republicans. I don’t like Democrats’ complaints about Republican pollsters “flooding the belt.” Not all polls with a House result that leans Republican actually have any official connection to the GOP. Also, to the extent that polls do have an effect—that is, they lean consistently toward Democrats or Republicans—our model adjusts for it. Besides, being the economics student at the University of Chicago, I mostly trust the market to sort everything out. Companies with a Republican effect will lose business and credibility in future election cycles if Democrats have a good night. In contrast, some traditional pollsters like Monmouth University don’t even publish final race numbers in the races they poll. If GOP-leaning companies like Trafalgar or InsiderAdvantage are willing to risk their credibility and Monmouth isn’t, that tells you something. However, we have come a long way from the Golden Age of Polling circa 2006-2012, when “gold standard” pollsters (live call telephone polls with transparent methodologies) could be counted on to set a reliable benchmark. No one in the polling or election forecasting community has a right to be so sure about what will happen on Tuesday. This can make you want to give up and trust the vibes or gut feeling about the race, which is a negative for Democrats. But the track record of the vibes is somewhere between junk and worse than junk, like in 2016 when insiders thought Hillary Clinton would take a cakewalk.

2 governor matches to watch | FiveThirtyEight

It’s also worth mentioning that the FiveThirtyEight Deluxe model is slightly more favorable to Senate Republicans than our poll-only version of the forecast, which essentially means that it predicts a bit of a Democratic bias in the polls, especially in some of the redder states. states like Ohio. So, in supporting Deluxe’s ​​view, I put a pinky on the scales for the view that the polls will again have a Democratic bias, while also being open to a simple serious bias in either direction. I think this is a big year for pollsters. In 2016, polling error wasn’t as bad, and pollsters had a semi-decent line of excuses from shifts in voter coalitions that made weighting polls by education important in a crazy October and November news cycle, including Comey’s letter. In 2020, COVID-19 presented real challenges for polling. This year, there aren’t as many surprises. Most Americans have abandoned COVID-19 precautions, there have been no late news events with obvious electoral implications, and Donald Trump is not on the ballot.

Question 2: How big will the turnout be?

Sorry to repeat the biggest cliché in election analysis, but if the polls are roughly in the right vicinity, control of the Senate will come down to turnout. If you care about the result and haven’t voted, you should. On that front, Democrats got some good news Sunday with two major network polls showing a relatively small turnout gap. (I’ll use the terms “turnout gap” and “enthusiasm gap” interchangeably here; in both cases, I’m referring to the difference in margin between a poll’s version of a likely voter and a registered voter.) The first, from our colleagues at ABC News and the Washington Post, showed Republicans 1 point ahead on the generic ballot among registered voters, but 2 points ahead among likely voters, leaving only a 1-point enthusiasm gap in favor of the GOP. Meanwhile, an NBC News poll had the generic ballot tied among registered voters, but Democrats 1 point ahead of likely voters, meaning there was actually a small enthusiasm gap in favor of Democrats. In both cases, this reflects improvements in Democratic enthusiasm from earlier this cycle. The earlier ABC News/Washington Post poll had shown a 4-point turnout gap favoring Republicans, and the earlier NBC News poll had Republicans gaining 2 points of their likely voter screen instead of helping Democrats. Most other polls show a modest enthusiasm gap in favor of Republicans. Republicans earn 3 points from the likely voter screen in CNN’s recent general poll, for example, 2 points from Siena College and the New York Times, and 1 point from Echelon Insights. But these numbers can be noisy. Marquette Law School’s early October poll of the U.S. Senate race in Wisconsin found the race tied among registered voters, but Republican Sen. Ron Johnson led by 6 points among likely voters. In the most recent Marquette poll, however, Johnson led by 3 among registered voters, but actually lost one point and led by 2 among likely voters. If there could be anything from a 6-point margin favoring Republicans (as in Marquette’s October poll) to a 1-point margin favoring Democrats (as in her latest), that creates a wide range of plausible results. And none of these scenarios are necessarily crazy. There was roughly a 6-point enthusiasm gap favoring the GOP in the 2010 midterms, for example. A turnout gap of any size favoring the Democrats would be unusual – usually voters from the opposition party are more enthusiastic about the midterms than the president’s party, and usually Republican voters are more likely to turn out than Democrats. But political alliances are shifting, with Democrats increasingly relying on college graduates, who are far more likely to turn out to vote. Moreover, there are some tangible signs of high democratic enthusiasm. Their House and Senate candidates have raised more money than Republicans, and Democrats have performed very well in a number of ballot initiatives and special elections over the summer, often based on superior turnout.

Before we get to the third question, a note on terminology. You’ll often hear us use the terms ‘universal ballot’, ‘house popular vote’ and ‘national environment’, but they mean somewhat different things. FiveThirtyEight’s generic poll tracker actually combines two types of polls. A set of polls asks voters which party they prefer to have control of Congress. Another guy asks them if they plan to vote for the Democratic or Republican candidate in their race for the US House. Since these questions tend to produce similar results,…