Given the ages of the signatories, this isn't all that heartening, and highlights the generational divide on the American left. If you want to predict the cultural trajectory, look at the views of those now getting PhDs. They've never been more left-wing than they are now. https://twitter.com/Harpers/status/1280495875165425670
There are a few big names on the Harper's list (although most are not), but there's also a sense of defeat to the effort that I can't shake, and part of it has to do with the fact that it's appearing in a magazine that most of us weren't even aware was still being published.