The United Auto Workers threatens to strike against General Motors, Ford, and Stellantis if tentative contract agreements are not reached by Thursday. UAW President Shawn Fain challenges President Biden's claim that the UAW supports his infrastructure plan, emphasizing the need for further negotiations. Former President Trump criticizes Biden's plan for all-electric cars and seeks UAW's endorsement. Some union leaders are skeptical of prioritizing reducing greenhouse gas emissions, while others view Biden as the most pro-union president. The strike could have political implications in Michigan, a key state for the Democratic party. Union support played a crucial role in Biden's campaign, but the UAW has not yet endorsed him for 2024.