I would strongly push back on these assumptions. The democratic structures outlined in the US constitutions are flawed by design and leads to the specious conclusion that democracy is impossible. Mass participation in the democratic process, smashing old structures, and reconstituting new structures will allow democracy and the public to thrive.
https://80000hours.org/podcast/episodes/glen-weyl-radically-...
The roles of such mandarins as Lippmann accelerate the regression of democracy. Contrast that with the democratically constructive roles of people (whistleblowers, participants in labor/antiwar/civil rights movement etc.). There is no impossibility theorem proving that people cannot socially organize into functioning democracies. Slavery looked like an inevitability at some point, and certainly Lippmanns in that era were enagaged in theorizing about effective slave-ownership rather than about ways to abolish slavery.
The "farce" becomes more farcical as power keeps getting concentrated more and more into the hands of the elites, a trend that is facilitated in no small ways by the mandarins. And farcically, they do not stop calling it a "democracy" even then.
The reps and bureaucrats are meant to be (public) servants. There can be and should be efforts to effectively organize such roles in bottom-up fashions, and to keep them in line with their stated roles. If the supply water is found to have impurity in it (some large ppm), the next step is to improve it, rather than taking sewage line as its alternative.
After re-reading your comment, I think we are on the same page, more or less. But Lippmann was writing about the very same work and propaganda that Bernays actively participated and "invented" during his time at CPI. Lippmann saw how it played out in 1917-1918, so he wrote about it. Bernays later wrote his book, but it wasn't journalistic work, he wrote from direct experience.
Please note, though, that recent experimental research has also pushed back a bit on the impact of propaganda and human gullibility [0].
[0]: https://press.princeton.edu/ideas/what-do-you-really-know-ab...
That is to say, what is now known as "PR" came from the military, who had trained people how to do this kind of work, e.g., in the role of "press agent".
It may have existed before the First World War^a but its popular use by the private sector may have happened only after more men had been trained in "PR" and had performed this work for the military.
[a] https://www.coursehero.com/tutors-problems/Accounting/970203...
It seems fair to say that there were many early adopters of this type of propaganda.