More than four years ago, former President Donald Trump’s administration accelerated the development and rollout of the covid-19 vaccine. The project, dubbed Operation Warp Speed, likely saved millions of lives. But a substantial number of Republican voters now identify as vaccine skeptics — and Trump rarely mentions what’s considered one of the great public health accomplishments in recent memory. “The Republicans don’t want to claim it,” Trump told an interviewer in late September. Instead, on at least 17 occasions this year, Trump has promised to cut funding to schools that mandate vaccines…