I don't believe that this is the commentary that Todd was aiming for at all but he may have unintentionally or unconsciously Incorporated these themes into the Joker.My genius thought this up in 5 seconds
Joker is a metacommentary on the white working class.
Joker represents said class. Short sighted. Blames everyone else for their problems that could have easily been avoided. And again, Fleck's pity rant at the end totally screamed how self centered the WWC are.
Noticed how Arthur tried to bond with Thomas Wayne only to be punched and threatened to be killed. Similar to how the wwc always cozy up to the rich conservatives assholes who keeps screwing them over.
Meanwhile, he just kills the Jay Leno character, the well meaning but condescending rich liberal who either gave a damn about him or at least was smart enough to fake it. And again, he at least called Joker on his toxic mindset, something a liberal is more likely to do.
The brown looking kids stealing Arthur's sign at the beginning of the movie represents the wwc's view on latinos trying take their jobs.
The first black psychiatrist not looking like she could be bothered to listened to Arthur is how the wwc's view black people as self centered and lazy. And I don't think I have to explain how Joker killing the second one symbolizes how it was the wwc who were committing terrorist attacks during the Civil Rights Era and even today.
Zazie's character represents how the wwc thinks black people should act. Always being kind and supportive to the wwc while not reciprocating the favor back. Noticed how during Joker's hallucinations of the relationship, we never see him imagine bonding with Zazie's daughter or support whatever thing Zazie does. Or even THINKS she does. The emotional support was one sided.
The clown protesters are the alt right. They put Joker on an undeserving pedal and it feeds into his toxic behavior. Like how Nazis do that towards the wwc "No you're not racist. They really are like that"
The three yuppies on the subway represents how the wwc won't do anything about a problem until it affects them. Harassing that woman? It's wrong, but what do you want me to do? Not my problem. When they turn their ire on me? I'm bringing out the gun.
Speaking of which, Arthur's complete mishandling of firearm safety is peak white working class.
So guys? "I agree" or "I really agree" or "what the fuck is wrong with you, NoName999"? :P
Edit: The 2nd therapist can also represent sincere liberals trying to listen to the wwc. And like Joker, the wwc kills that kindness by continuing to vote Republican