I feel that the first season was pretty neutral, maybe kind of left-leaning aesthetically, but it also aired way back in 2013.
The newer episodes are dropping more fashy lines. The Unity episode where Rick frames some minority alien group for something, and then says "sheesh, don't blame me it's the police who are racist"
Or the "future crystals" where rick keeps getting routed through fascist alternate universes with nazi morties, only to end up with a wasp rick where the entire wasp Smith family eats the (Black) math teacher larvae. Not exactly subtle.
The whole premise of the show also became even more over of a power fantasy in seasons 3/4.
https://www.youtube.com/watch?v=gMILvY_FJj8
I feel like the show post-season 3 is basically full of contempt for the audience and giving them what they want while insulting them for wanting it.
That makes sense actually.
Dan Harmon is center-left (in our terms, not american vocabulary), and I don't think he has strong political views.