President Biden made history on Tuesday when he joined members of the United Auto Workers union on a picket line outside Detroit as they strike for better pay and benefits from the Big Three automakers.Biden is walking a political tightrope. He wants a better contract for workers–and to win union members' votes in battleground states. He also wants to support carmakers as they transition to a future of electric vehicles.NPR's Mary Louise Kelly speaks with Micheline Maynard, the author of The End of Detroit: How the Big Three Lost Their Grip on the American Car Market, to understand how profitable the big carmakers are right now. And NPR's Michel Martin speaks with historian Jefferson Cowie about the unprecedented nature of Biden walking the picket lines.Email us at considerthis@npr.org.