Alex said that since clowns are cool, we shouldn’t use that word as an insult.
While I’ve always loved clowns, never had coulrophobia, had a Pierrot doll when I was a li’l girl, met great clowns when the circus came to town, had my life saved by a clown, have worked with clowns and clowning… I still feel like “clown” or “clowning” in the polysemic meaning “to do foolish things” is, well, it’s part of the intent of many (not all) clown acts. The character is behaving foolishly, often for satirical purposes. Calling a politician a “clown” might be a li’l bit “Your joke, but worse” but it’s not intended as an insult to clowns. It’s a testament to the efficacy of their satire.
It’s like saying “wow my boss is a real Mr Burns” isn’t meant as an insult to Harry Shearer or to his performance as Montgomery Burns on the Simpsons. It’s a li’l too on the nose, a little “well, duh, since Mr Burns is intended to caricature that kind of behavior” but it’s not implying that Harry Shearer is as bad as your boss is. That’s an imperfect analogy since “clown” and “clowning” can also be used to refer to the act of performing itself (no one is saying “My boss is behaving like a damned voice actor”) but it hopefully gets the gist across.
It’d be like saying that the expression “You’ve got to be kidding” would be an insult to comedians.
All that said, be aware that the fash have tried to appropriate “clown world” like they did the OK sign and frogs. Which sucks because it was useful, it was less ableist than many other insults.