The Vote And Voting Problems, Pre-Election Day 2020

Dylan Doherty from Hamtramck, Michigan: I understand that Democrats are more likely to vote absentee/mail-in, but why would that lead to a “red mirage”/”blue shift”? Are in-person ballots all counted first and then absentee ballots? Why would that be?

The short answer is that it depends on the state. But it’s true that some states may see a “blue shift” or “red mirage” based on how their votes are counted, because some will count Republican-leaning Election Day votes before many Democratic-leaning mail ballots. After all, we know that mail ballots will be disproportionately more Democratic — in 19 states where there’s party registration, around 51 percent of mail or in-person early votes have been cast by registered Democrats, compared with just about 26 percent by Republicans, based on data from Michael McDonald at the University of Florida. However, the count pattern will vary from state to state, and some could initially have more Democratic-leaning results that then trend Republican.

Pennsylvania is a battleground state that might see a notable shift in a Democratic direction, in part because election officials cannot begin processing mail ballots until the morning of Election Day. As such, we can probably expect most Election Day votes to be counted that night, but we can’t know for sure how many mail ballots will have been tallied. A large number of mail ballots will have already been returned, which could help officials get into a position to count a sizable share of them. But the vote count was very slow in some parts of the state during the June presidential primary, and even with that experience under their belt, election officials will have far more ballots to count in the general election. And there’s little question that mail ballots are going to lean heavily toward Biden, as recent Pennsylvania polls have shown that around three-fourths of voters who plan to vote by mail or who have already voted back Biden.

However, other states could actually see a “red shift” as their counts wear on. Florida begins processing mail ballots 22 days before the election, and state law requires county election officials to report all tabulated early and mail ballots within 30 minutes of polls closing, which is 7 p.m. Eastern in most of the state. So the early rush to send in mail ballots this year could mean that a huge Democratic-leaning tranche of ballots will be reported fairly early on Election Night and ahead of many Republican-leaning Election Day ballots. The final result could then come down to whether a Democratic lead will hold up, instead of a Republican one like in some other states.

On Wednesday, Iowa’s state Supreme Court upheld a Republican-backed law that prevents county elections commissioners from filling in missing information on absentee ballot request forms using voter registration data. Instead, commissioners must contact voters to fix the forms themselves. It’s the latest Republican victory in the state after a previous ruling invalidated tens of thousands of ballot request forms that had been sent to voters with their information already filled in, deciding that those applications should have been sent to voters blank.

A.S. from New Jersey: Have you considered factors such as rejected absentee ballots (which would affect Democrats more because they’re more likely to use those) in your probability estimations?

No, our model doesn’t attempt to account for anything that happens after ballots are cast, such as mail ballots being rejected or Trump successfully challenging the outcome of the election. We’re not trying to dismiss these concerns; they’re just outside the scope of a statistical analysis. Things like human error or the whims of the president can’t be modeled!

If you’re interested in reading more about rejected ballots, I humbly recommend this article I wrote last week. It’s certainly concerning for democracy that hundreds of thousands of otherwise eligible voters will probably see their ballots invalidated this year; however, I would be surprised if it actually affected the outcome of the election. First of all, only 30-40 percent of ballots are expected to be cast by mail this year. Second, only about 1 percent of mail ballots are rejected. That means an election would have to be within 0.3 or 0.4 percentage points for rejected mail ballots to be decisive. And even in that case, it’s not as if all mail ballots are cast for Democrats. So even a Democratic lead of 0.3 or 0.4 points probably wouldn’t be erased (just narrowed) by rejected mail ballots.

Of course, this is a very rough, hypothetical example. In some states there will be a lot more than 30 percent of votes cast by mail. Furthermore, the rejection rate could be higher this year because so many people are voting by mail for the first time and are unfamiliar with the rules (although experts are optimistic that this will be mitigated by states extending their ballot-receipt deadlines, allowing voters to fix mistakes on their ballot and making ballot instructions clearer). So we can’t totally rule out rejected ballots being decisive in a hyper-close race. I just think it’s unlikely.