As 2020 wound down, there were good reasons to believe that the death toll during the pandemic’s first year might have been worse in red America. There were also good reasons to think it might have been worse in blue America.

Conservative areas tend to be older, less prosperous and more hostile to mask-wearing, all of which can exacerbate the spread or severity of COVID-19. Liberal areas, for their part, are home both to more busy international airports and more Americans who suffer the health consequences of racial discrimination.

But it turned out that these differences largely offset each other in 2020 — or maybe they didn’t matter as much as some people assumed. Either way, the per capita death toll in blue America and red America was similar by the final weeks of 2020.

It was only a few percentage points higher in counties where Donald Trump had won at least 60% of the vote than in counties where Joe Biden crossed that threshold. In counties where neither candidate won 60%, the death toll was higher than in either Trump or Biden counties. There simply was not a strong partisan pattern to COVID during the first year that it was circulating in the United States.

Then the vaccines arrived.

They proved so powerful, and the partisan attitudes toward them so different, that a gap in COVID’s death toll quickly emerged.

The gap in COVID’s death toll between red and blue America has grown faster over the past month than at any previous point.

In October, 25 out of every 100,000 residents of heavily Trump counties died from COVID, more than three times higher than the rate in heavily Biden counties (7.8 per 100,000). October was the fifth consecutive month that the percentage gap between the death rates in Trump counties and Biden counties widened.

Some conservative writers have tried to claim that the gap may stem from regional differences in weather or age, but those arguments fall apart under scrutiny. (If weather or age were a major reason, the pattern would have begun to appear last year.) The true explanation is straightforward: The vaccines are remarkably effective at preventing severe COVID, and almost 40% of Republican adults remain unvaccinated, compared with about 10% of Democratic adults.

Charles Gaba, a Democratic health care analyst, has pointed out that the gap is also evident at finer gradations of political analysis: Counties where Trump received at least 70% of the vote have an even higher average COVID death toll than counties where Trump won at least 60%.

As a result, COVID deaths have been concentrated in counties outside of major metropolitan areas. Many of these are in red states, while others are in red parts of blue or purple states, like Arizona, Michigan, Nevada, New Mexico, Pennsylvania, Oregon, Virginia and even California.

This situation is a tragedy, in which irrational fears about vaccine side effects have overwhelmed rational fears about a deadly virus. It stems from disinformation — promoted by right-wing media, like Rupert Murdoch’s Fox News, the Sinclair Broadcast Group and online sources — that preys on the distrust that results from stagnant living standards.

A peak?

The future of COVID is uncertain, but I do think it’s possible that the partisan gap in COVID deaths reached its peak last month. There are two main reasons to expect the gap may soon shrink.

One, the new antiviral treatments from Pfizer and Merck seem likely to reduce COVID deaths everywhere, and especially in the places where they are most common. These treatments, along with the vaccines, may eventually turn this coronavirus into just another manageable virus.

Two, red America has probably built up more natural immunity to COVID — from prior infections — than blue America, because the hostility to vaccination and social distancing has caused the virus to spread more widely. A buildup in natural immunity may be one reason that the partisan gap in new COVID cases has shrunk recently.

Death trends tend to lag case trends by a few weeks, which suggests the gap in deaths will shrink in November.

Still, nobody knows what will happen next. Much of the recent decline in caseloads is mysterious, which means it may not last. And the immunity from vaccination appears to be much stronger than the immunity from infection, which means that conservative Americans will probably continue to suffer an outsized amount of unnecessary illness and death.

© 2021 The New York Times Company