A potential strike by U.S. auto workers in September would be a high-stakes problem for President Biden, who’s trying to balance his push for electric vehicles with his self-description as “the most pro-union president ever.”

Driving the news: The United Auto Workers worries that EV factories won’t employ as many people as traditional plants, and that new battery factories spurred by the president’s tax incentives will pay lower wages.

Why it matters: In addition to the political implications, a work stoppage by nearly 150,000 UAW workers at GM, Ford and Stellantis would result in an economic loss of more than $5 billion after 10 days, according to Anderson Economic Group.

Zoom in: UAW members will vote this week on whether to authorize their fiery new leader, Shawn Fain, to call a strike against Detroit carmakers when their contract expires Sept. 14.