Good reading, if a bit of a slog, as Croly never used one word when three could be made to fit. However, if you want to see the entire “Progressive” (e.g., Fabian Socialist) playbook the American left has been running for the past century laid out in clear detail, this book is it.
"Progressive" is just a word that can mean whatever you might want it to mean today."
This is probably the foundational issue you and I face. You believe progressives are just playing cute games with a soft-sounding word. I do not. This word is just as meaningful in describing bureaucratic despotism/administrative state as it was during the Progressive era. Because of this singular word's meaningfulness, Hillsdale College distributes educational videos describing the specific dangers of the ideology of Progressivism and their rejection of the U.S. Constitution. With all of that said, Croly's "Promise" is one of the most important books by progressives outlining progressivism.
In Nationalism and Popular Rule, Theodore Roosevelt recommended Croly's Promise this way:
In Mr. Herbert Croly's "Promise of American Life," the most profound and illuminating study of our National conditions which has appeared for many years, especial emphasis is laid on the assertion that the whole point of our governmental experiment lies in the fact that it is a genuine effort to achieve true democracy—both political and industrial.
Knowing that the Roosevelt Presidency was so terrible is not as important as knowing why it was so terrible. It was terrible because it was so progressive, this book recommendation says it all and gives meaning and substance to the word.
Progressive ideology is both a very real threat, as well as a very specific thing. I recorded this audio book specifically for people such as yourself, except, but for those who do actually want to know. This book is very much a "communist manifesto" of sorts for Progressivism.
BM