@tomiahonen
I'm sure you are familiar with Reich's background as former Labor Secretary and public policy professor. I don't believe he says he's a statistics expert, but once a political insider and still an avid political observer.
I follow him for his expertise on some areas of government policy. It appeared to me he must be bothered by the closeness of whatever polls he's observing.
I mostly follow your poll analysis, and observe the fund raising advantage Harris has among small donors and her superior rally sizes, which to me suggest she has an enthusiasm advantage. Reich only mentioned his concern of close polls.
Thanks for responding.