Lippmann says the answer is two parts:
1. For voters, improve their ability to make the right choice via education and representative (not direct) democracy.
2. For politicians, improve data so they can make better choices.
Interestingly, (2) sounds a lot like data.gov, a century before data.gov!
Propaganda.
> For voters, improve their ability to make the right choice via education and representative (not direct) democracy
The common theme of Le Bon and Bernays was that such groups as "the voters" are inherently not capable of making deliberate choices, and those choices will be made for them by propagandists. I find that depressing, but their arguments for it are convincing.
It wasn't always the case that "fake news" aka propaganda made so much headway. The degree to which that was happening from ~2015 until now is a unique phenomenon not paralleled since Lippmann's time.