By this measure, Arizona again seems relatively insulated from suppressed turnout: The state currently has just 18 known cases, or 2.5 cases per million residents. Florida and Illinois, on the other hand, have somewhat higher numbers. There are 138 known cases in Florida, or 6.4 per million, and 95 in Illinois, or 7.5 cases per million. Both are still beneath the national average.
All of these figures are better than those in France, where voters went to the polls in local elections on Sunday. There, turnout was down by 20 percent from the last election in 2014. It was a significant decline in turnout, but perhaps not one that bodes especially poorly for the elections in the U.S. on Tuesday. After all, there are more than 83 cases per million French resident, or more than 10 times the rate of Illinois, and there is no substantial early voting.
There is no reason to assume that American and French voters will respond to the coronavirus threat in the same way. But if they did, the turnout in today’s primaries would presumably remain relatively strong.
If turnout did drop because of coronavirus, it’s hard to say which candidate would benefit. Older voters would seem likeliest to stay home. They face the greatest health risks from coronavirus, and older Democrats tend to be most concerned about it, according to data from Civiqs. A lower turnout among older voters would tend to hurt Joe Biden, who has won older voters by a wide margin.
On the other hand, older voters are likeliest to have already voted, and they are the most reliable voters in general.
Confirmed cases tend to be concentrated in metropolitan areas, where Bernie Sanders has usually fared best in the contests since South Carolina. In Illinois, for instance, most cases are in Cook County, which includes Chicago and around half of Illinois Democrats. Cook County has 70 known coronavirus cases, or 13.4 per million residents. One could argue that turnout is likeliest to drop there, and that might be bad news for Mr. Sanders, who seems likely to get swept in the state’s rural areas and suburbs.
Ultimately, even a significant coronavirus turnout effect would be unlikely to change the trajectory of the race. Mr. Biden leads by a wide margin in all three states, based on the polls and recent election results. If he wins by anything like the kind of margins suggested by the polls, he could end the night with an all but insurmountable lead in the pledged delegate count.