G raham Platner , the oyster farmer rocketing to Democratic celebrity nationally as he campaigns for Senate in Maine, is testing two hypotheses that could reset his party’s direction: that the censorious left can sometimes ignore past, regretted transgressions such as fascist tattoos or bigoted social-media posts; and that voters in the centre and even on the populist right are far more drawn to economic causes such as universal health care than they are repelled by cultural ones he also believes in, such as welcoming transgender athletes into girls’ sports.

Mr Platner’s commitment to the second hypothesis has already helped him prove the first. Revelations of past misbehaviour have not slowed his momentum. A little hypocrisy in politics should surprise no one; it is simply more obvious on the high-church left, as it also is on the Evangelical right, because of the particular stress those movements place on purity.…