https://www.scientificamerican.com/article/trump-vs-biden-how-covid-19-will-affect-voting-for-president1/

In late April Democrat Kweisi Mfume of Maryland won a special election for a seat in the U.S. House of Representatives in a landslide victory against his Republican rival. More remarkable than his win, which garnered three quarters of the vote, however, was that more than 110,000 Baltimoreans in the district cast their ballot by mail. Only 1,000 voted at one of three polling centers open there. In Georgia’s primaries in early June, more than one million voters used mail-in ballots, a huge increase over previous elections. In Wisconsin, voters are suing for greater access to such ballots because many polling places have closed in response to COVID-19—which has made it much harder to vote in person in the state’s primaries.

These are just some of the political battles that have played out during the pandemic, when many people feel it is too risky to gather in public to do things such as vote in person. On June 2 eight states and Washington, D.C., held their primary elections, four of which had been postponed because of the disease. Half of the eight states had turnouts surpassing their 2016 levels—after taking extra efforts to ensure citizens received vote-by-mail ballots. But the others fell short despite such measures.