radical
Explanation
The Joke
A person lies on a therapist's couch, lamenting: "I feel like to fit in I need more student politics otherwise I'm not fighting against entrenched power." The therapist-like figure responds: "But to be honest, I'm not a radical. I have a family and a comfortable life. I have a retirement plan. I am literally the establishment." The person then has a moment of self-awareness: "I guess what I really want is a belief system that's precisely radical enough to signal virtue to my peers, but not radical enough to risk any actual change in my comfortable life. I want revolution without implementation."
In the final panel, someone challenges them: "Has it ever occurred to you that you ARE the entrenched power now?" The person responds defiantly: "But I shared all the right petitions!" -- clinging to the idea that performative online activism counts as genuine resistance to power structures they are now part of.
The Humor
The comic skewers performative radicalism -- the phenomenon of comfortable, established people who adopt the language of revolution and resistance while having no intention of actually disrupting the systems that benefit them. The punchline about sharing petitions perfectly captures the gap between feeling like a radical and actually being one. The character wants the social cachet of being a rebel without any of the costs, and their final defense ("But I shared all the right petitions!") is a devastating portrait of slacktivism. It is particularly sharp because it targets exactly the kind of educated, politically aware person who would read SMBC -- making the audience uncomfortably complicit in the joke.
References
The comic touches on the concept of "slacktivism" or "performative activism" -- engaging in low-effort political gestures (sharing posts, signing online petitions) as a substitute for meaningful political action. It also references the broader sociological observation that many people who identify as politically radical are, by any material measure, members of the comfortable establishment they claim to oppose.