Also, I’ve observed a rhetorical trend among the “anti-bigness” crowd towards defining “monopoly” down:
“You may think a monopoly is an overwhelmingly dominant position as a supplier of a good or service, but that’s just naive popular economics! Acshually, according to the latest economic theories (by economists who share our politics), a monopoly is any firm that is big enough to have market power—like pricing power—to do things that can harm a competitor unfairly.”
Us dummies will keep calling that competition.
While the misuse of the term monopoly is annoying, that's quite the misleading comment. You're allowed to disagree with what policy is a good idea, but laws like the linked do exist, and they were seen as pro-competitive in their time.
Today you can consider that "just business", and therefore "part of competing", but the were laws with the intention of allowing/disallowing types of tactics. E.g., you can't compete by leveraging your volume (see attached link), so you have to focus on making your service good.
The assumption made by a these people is that if there are so majy companies getting that big, there must be general disrespect of these laws. And correlating with the undisputed fact that antitrust enforcement did change.
https://en.wikipedia.org/wiki/Robinson%E2%80%93Patman_Act?wp...
What does Robinson-Patman enforcement have to do with the economic definition of a monopoly?
Robinson-Patman applies to every supplier and every retailer, not just monopolies, which is what makes it so difficult to equitably enforce. So it hasn’t been.