I think it's time to look in the mirror and see that your preconceptions and biases are making you overlook reality. Like.. obvious reality. Reality that's so obvious it's in Wikipedia info boxes.
Honestly, the problem isn't even with all Oxford undergraduate degrees, just a slice of PPE and adjacent students who are vastly overrepresented in politics.
(My background: Leeds BA, Oxford MSc/DPhil. Don't like Starmer, though, despite our similar university choices...)
There's a number of components to the sentence I responded to:
> same schools
and
> together
An undergrad studying PPE and postgrad studying Law are not "going to Oxford together." Instead of trying to uncover some insidious bias on my end, I'd strongly recommend doing more than a surface level scan of Wikipedia pages to "win the argument," so to speak.