Everyone has political motivations. You're going to entirely discount a group that studies migration from the most esteemed university in the UK because you don't like what someone puts on their twitter feed?
This is perfectly rational. Do you trust political polling from pollsters with party affiliation? I hope not.
Over the last couple years, I've started mentally putting a "P(BULLSHIT)" next to every source I read. The estimate keeps growing.
While you might want to make this an ad hominem attack, all I can say is that my probability estimates are pretty darn bipartisan.
Isn't usually the most "esteemed" establishments that are closer to the party line?
That's par for the course of being "esteemed".