@hightor,
I believe your "castigation' description overstates the content of my post. I was referring mostly to the author's odd (in my view) statements about ignoring inconvenient states that aren't presumed to be truly representative of his concepts of the Democrat electorate. This appears to involve flawed attitudes and assumptions similar to those the Clinton campaign made in 2016. Hillary's threats to shut down the coal industry (unnecessary, as the economics of new technology and the gas boom was doing it already); her description of the voters who might favor her opponent as "deplorables"; and her remarkable decision to skip campaigning in states also seen as not completely representative of the assumed Democrat electorate -- certainly didn't help her in her failed effort to win the Presidency.
The DNC continues to play with and adjust important details of its primary system, including it's own process for the final stages in the Convention. I don't claim to know their motives, but much of it looks like an effort to tame their emerging far left wing contingent, and rig the system to deliver a preferred outcome, while preserving an exaggerated appearance of democratic process. So far it isn't evident to me that these efforts have improved its situation very much. An element of "progressive" thinking appears to be at work here - the notion that self-appointed savants can design processes to guide the behaviors of others, and do so without unexpected side effects.