For reference, when I refer to leftist ideals I'm referring to socialism/communism rather than the ideals of liberal/Democrat politicians that many think are "the left" but are actually just barely left of the political line if not entirely center or a bit to the right.
Since the shows beginning it had a habit of playing both sides of an issue, or in some cases pretty early on even leaning more to the conservative right. In more recent years though I feel the show has moved strongly to the left and has decided to set both feet firmly on one side of the line. Examples of recent left wing ideology in the show include the more recent appearances of manbearpig where they reversed their stance of denying climate change (while not an inherently leftist position it did represent a big shift away from the hard right takes they made in the past), the Amazon/bike parade arc which criticized Amazon/capitalism and which showed unionization and socialist ideas in a non mocking way, the SoDoSoPa arc which targeted liberal led gentrification and showed how it just further marginalized the lower income community and eventually out priced even the middle class residents, the entire Garrison as Trump arc which was just several seasons of absolutely shitting on the right with only a few occasional light jabs at the left, the toilet paper episode which again strongly criticized capitalism and pointed out just one of the many billion dollar industries that are destroying our planet and taking advantage of society for profit, and the panderverse special which strongly criticized capitalism again by targeting billionaires who would rather fuck around in space than use their resources to save the planet. While the show hasn't outright supported socialism or anything, there has been a clear and unmistakable shift towards the left in the show's messaging and I'd love to hear the communities opinion on this observation.