The participating companies all insist that the effort, called Time to Vote, is nonpartisan. They say they are concerned with persistently low voter turnout rates, and want their employees and customers to get to the polls on Nov. 6.

“For democracy to work, people have to vote,” said Chip Bergh, the chief executive of Levi Strauss & Co., which was one of the companies that helped organize the effort. “The greatest threat to democracy is apathy.”

However civic-minded, the effort comes ahead of a hotly contested midterm election in which Democrats have a good chance of retaking control of the House, and possibly the Senate.

“Getting out the vote should be a nonpartisan issue,” said Aaron Chatterji, a professor at Duke University’s Fuqua School of Business. “But in this day and age, it will inevitably be seen as political. So many of those companies have publicly tangled with the president on race issues, immigration and climate change.”

Patagonia, for example, is currently suing Mr. Trump for his decision to shrink the size of several national monuments. Walmart’s chief executive, Doug McMillon, chastised Mr. Trump after Charlottesville. And Lyft made a symbolic $1 million donation to the American Civil Liberties Union after Mr. Trump announced his initial travel ban targeting Muslim-majority countries last year.