Whitmer, Pritzker, Manchin, to name a few. Oh yeah, and Shapiro. Columnists in today's NYT discussed them. https://www.nytimes.com/2024/07/04/opinion/biden-alternative-democratic-ticket.html?unlocked_article_code=1.400.VoUn.IP8lLNw5G3w3&smid=url-share (Pritzker was discussed in an earlier column).

Many are appealing and all are risky. To me, so is Biden. I'd like to see him have the courage to try and convince the nation at an open convention that staying in is not a stubborn or selfish choice. https://marcus17043.medium.com/an-outside-the-box-suggestion-for-biden-6c336f4a9908