People remember history with more passion than precision. The story of Billy the Kid, as the outlaw William Bonney is called, has been mythologised more than most. There used to be a museum in White’s City, New Mexico, with a sign that read: “We don’t have the gun that killed Billy the Kid. Two other museums have it.” In the course of a “cattle war” in Lincoln County, New Mexico, around 1880, Bonney murdered at least nine people – 21 if you get your history from Woody Guthrie’s ballads – but in the American historical imagination he retains a romantic glow.

Wishful thinking about Billy the Kid has lately taken a turn for the absurd. Bill Richardson, the publicity-loving governor of New Mexico and an also-ran in the 2008 Democratic presidential primaries, has for years been sympathetic to the idea of actually pardoning Bonney. He has sought input from historians and lesser citizens through a process that ended at the weekend. Mr Richardson is expected to reach a decision on pardoning Billy the Kid by New Year’s eve.

Governors in the US have the authority to pardon the convicted, but this authority has been exercised with unusual frivolity in recent decades. In 1987, Michael Dukakis revoked the banishment of the antinomian preacher Anne Hutchinson, expelled from the Massachusetts Bay Colony in 1638 over doctrinal differences concerning salvation by grace and salvation by works. Hutchinson is thus welcome to return to Boston any time, should reports that she was scalped by marauding Indians near New York in 1643 prove erroneous.