Political doesn't necessarily mean "Republican vs Democrats".
That is true, trivially true and it surprises me that I have to repeat that yes, it is what I assumed when I initially rejected your accusation. I thought "not political in any sense" was about as explicit as I could be without just sounding awkwardly verbose.
In XKCD's case, it's "STEM majors vs liberal arts majors."
I cannot imagine how anyone who read a significant sample of XKCD comics would claim this. It is about in jokes - witty (or intended to be witty) references to ideas that are funny if you happen to either know about the technical factoid or are interested enough in that kind of thing to google it. If anything it is far too well, self absorbed in it's own STEMiness for it to bother being political much along the STEM/arts axis. It doesn't even seem to bother to try to score points along the nerds/copyright axis. It takes its cheap shots at the expense of nerds almost exclusively.
Take a look at 863, or the alt text of 764. Liberal arts majors are identified as an outgroup in XKCD's "warning" at the bottom of each page. It's as transparent as Dr Pepper 10 saying "It's not for women!!"
An episode of the Noddy animated series has the following plot.
Noddy needs to go pick up Martha Monkey at the station. But it's such a nice, sunny day that he would prefer to play around outside. He gets an idea to solve this dilemma. He casts a duplication spell on himself and his car and tells the duplicate to go fetch Martha while he goes out to play. Later, Noddy is out having fun when he suddenly spots his duplicate. It turns out that the duplicate also preferred playing outside to doing the errand so he also cast a duplication spell. Then they see another duplicate, and another...
I think this story makes for a nice simple illustration of one of our perennial decision theoretic issues: When making decisions you should take into account that agents identical to yourself will make the same decision in the same situation. A common real-life example of the Noddy problem is when we try to pawn off our dietary problems to our future selves.