I can see how this stream definitely could give someone an impression that there aren't many liberals.... But I can assure you, it's been overwhelmingly right-wing for years....years before President Biden was elected anyway.
One possibility that I've pondered is that maybe a bunch of the people who got kicked off Twitter, Facebook, etc ended up here. PoliticsToo might leech some of the libs away from here too idk.... Not sure when exactly that stream was started nor the effect, but it seems possible.