Imagine, for a moment, that you are in the thick of the Democratic presidential primary of 1972. Figures like Edmund Muskie, George McGovern, Hubert Humphrey, and Shirley Chisholm are vying for the nomination. In the course of a discussion over who is the best choice to take on Nixon, someone offers a word of warning: “We don’t want another Cox, do we?”

If that name means little to you in the context of Democratic politics today, it’s not because you’re missing some vital part of the political conversation from 1972. Indeed, it probably would have meant little more to someone hearing it in that year. It refers to James M. Cox, the Democratic nominee in 1920, who lost to Warren Harding by a whopping twenty-four points, the most decisive margin in US history.

If the idea of bringing up a bad loss from the 1920s in the context of the 1970s seems strange, it is worth asking why, today, the comparison between Bernie Sanders and George McGovern’s ill-fated campaign half a century ago seems somehow less strange. Indeed, since Sanders’s first run in 2016, the comparison with McGovern has been raised again and again by his opponents.