The United Automobile Workers gave a thumbs-up Friday to General Motors’ plans to build its latest electric vehicle at a Michigan plant, but the union isn’t relenting in its campaign to bring back work at factories the carmaker idled elsewhere.

Neither are U.S. politicians. The shutdown of GM’s plants in Lordstown and Warren, Ohio, along with its Detroit-Hamtramck site in Michigan have become an early flashpoint in the 2020 presidential campaign since they were announced last November.