A battle over voting by mail is again being waged in an electoral contest. But now it’s Amazon that opposes a mail-ballot election in order to thwart a unionization effort at an Alabama fulfillment center.

In November, Jeff Bezos, Amazon’s chief executive, rejected Donald Trump’s falsehoods about voter fraud, writing on Instagram just after the election, “By voting in record numbers, the American people proved again that our democracy is strong.”

Now, however, Amazon’s opposition to mail balloting threatens to undermine workplace democracy. In the era of Covid-19, it also endangers public health.

The voters in the election are nearly 6,000 warehouse employees at an Amazon Robotics sortable fulfillment center in Bessemer, Ala., a Birmingham suburb that was once a center of steel production. They receive, sort and package goods delivered across the South. They will cast ballots to decide whether to be represented by the Retail, Wholesale and Department Store Union, a part of the United Food and Commercial Workers. With 40 coronavirus cases recently found at the warehouse, the union sought a mail-ballot election. The ballots are currently scheduled to be sent out on Feb. 8 and must be received by March 29.

If the Bessemer warehouse employees vote for union representation, it will be the first unionized Amazon workplace in the nation — a pivotal electoral victory for labor.

Union elections are supposed to be modeled on political elections; both are systems of representative democracy. Employees, like citizens, are entitled to vote for “representatives of their own choosing,” according to the National Labor Relations Act. The authors of the act called this “industrial democracy.”

But Amazon opposes union representation, and for decades the company has used weapons such as surveillance programs, anti-union websites, text messages and videos to suppress labor organizing.

The campaign against mail balloting in union elections is Amazon’s latest assault on industrial democracy. And it is one corrosive to political democracy as well.

Following the lead of state legislatures and courts during the pandemic, the National Labor Relations Board authorized mail voting. Since Covid’s onset, about 90 percent of union elections have been conducted by mail.