This year’s Electoral College map may show another “blue shift.” Here’s why

Counting ballots may take longer in some locations than others.

In presidential elections, this difference can cause a candidate’s early lead in a state to change as more communities announce their results in the hours and sometimes days after polls close on Election Day.

In 2020, the phenomenon known as the “red mirage” or “blue shift” turned the hue of several seemingly red states — where then-Republican President Donald Trump appeared to be leading over then-Democratic candidate Joe Biden — blue.

Trump and his allies responded by linking this change to unfounded claims of widespread voter fraud in mail-in ballots in states like Arizona, Georgia, Michigan, Nevada and Pennsylvania.

But in reality, this was due to partisan differences in where voters lived and their preferred method of voting, as well as laws in some states that slowed vote counting.

Republicans in smaller counties vote in person, while Democrats in larger counties vote by mail

There are two trends that explain the range of election result reporting speeds:

• Voters in urban, more densely populated communities are generally more Democratic-leaning, and smaller, rural communities are often more Republican-leaning.

• Republicans tend to vote in person, while Democrats have led the surge in mail-in voting since the 2020 pandemic election, as recent elections have shown. (A new NPR/PBS News/Marist poll suggests this trend is likely to continue in the 2024 general election.)

An analysis of the 2020 election by the MIT Election Data and Science Lab concluded that the differences in the speed at which counties reported their results “were due to the fact that smaller and more rural counties that favored Trump “Hundreds of counties and hundreds of thousands of voters were able to share their ballots before the counties.”

The analysis found that many of these larger counties took longer to report results because of the large volumes of mail-in ballots they received. Counting mail-in ballots that arrived after Election Day also slowed in some states.

And there’s another strange factor to consider: whether a state’s laws allow election officials to process mail-in ballots before Election Day.

Some state election laws slow the counting of mail-in ballots

There is a deep process in election administration called “pre-canvassing.”

It covers all the steps needed to prepare mail-in ballots for scanning, including verifying voter signatures on return envelopes, opening those envelopes, and smoothing the ballots inside.

When that processing is allowed to begin varies by state, and the MIT analysis found that states with laws allowing pre-election before Election Day were able to report results more quickly in 2020.

For this year’s presidential election, the states that do not allow processing before Election Day include two important swing states: Pennsylvania and Wisconsin.

While Arizona allows processing once a complete ballot is received, election officials in this swing state say there will likely be delays in reporting because hundreds of thousands of voters are not expected to cast their mail-in ballots until Election Day.

Still, some election observers say the experience election officials have had with mail-in ballots since the 2020 election, and that some mail-in voters are returning to in-person voting in 2020, could help shorten the time it takes to complete the count this year becomes.

But especially if the presidential race turns out to be close in one state, additional patience may be needed before voters see the true face of the 2024 electoral map.

Edited by Benjamin Swasey

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