Liberal by definition is anti-racist. A major tenet of liberalism is egalitarianism and it's what allows free market capitalism.
Maybe you should go educate yourself about what Liberalism is before appointing yourself the racism police on Hackernews.
I'm a liberal and I've said I prefer not having more racists in California with illiberal sentiment. That is the opposite of racist.
There is a long history of America enforcing white racial integrity which you seem to be naive to. As a native Californian I think it's fair to be weary.
I stand by not wanting more transplants in my state and it's not just me.
In my opinion, bigotry in mainstream public discourse is never going to happen. It's a feature of capitalism and why you won't see gas vans as long as we remain a capitalist society.
But don't let me dissuade you from advocating for your beliefs.
I've seen what they post when they're "speaking their mind"
It almost always devolves into "jokes" about getting state approval to shoot immigrants, refugees, minorities in open ranges, or providing "helicopter rides" - a reference to dropping people from helicopters.
This is what currently unifies the right wing of US politics.
Whether or not all populations on Earth are mixing enough to prevent speciation remains to be seen. But the process begins with the kind of mutations documented in the article.
But if companies allow extremists on their platforms then the moderates will leave. It's not so much a paradox but a cause and effect.