Here it is important to distinguish wish-casting from reality, as reinforced in conversations with Cuomo allies and party officials like Mr. Jacobs. “Joe Biden is going to be our nominee,” he said.

Instead, the Cuomo flirtation, such as it is, seems most instructive for what it says about those drawn to it, reviving a persistent trope among Trump-era Democrats: the romanticizing of prospective party saviors, even at this point in the nominating calendar, a vice that has yielded all manner of campaign fantasies in recent history…

Some past adversaries have been less charitable, urging new converts not to be persuaded. They say that while Mr. Cuomo’s news conferences might be well calibrated, New York could have done more earlier in the month to protect its citizens, noting that officials in states like California and Ohio seemed to act more decisively at times.