LITCHFIELD, New Hampshire—A collection of flyers lay scattered on the doorstep of a home in this small suburban town last week. Two of the door hangers, telltale signs of an unanswered canvassing call, were from America PAC, a political group bankrolled by Elon Musk. A third, crumpled and warped from moisture, was from the Sentinel Action Fund, a conservative super PAC once affiliated with the Heritage Foundation’s lobbying arm.
