“It’s a tribal issue,” said Mr. Murphy, who has worked for Senator Mitt Romney of Utah, former Florida Gov. Jeb Bush and other moderate Republicans. Mr. Murphy, a fan of electric vehicles, founded the EV Politics Project to try to get Republicans to stop bashing them — a lonely struggle.

“If you can’t crack the Republican problem there is no way you can get to these targets,” Mr. Murphy said, referring to the E.P.A.’s emission goals. “They are going to run out of Democrats.”