He does acknowledge that there is a correlation between religiosity and racism:
But it seems there is almost a direct correlation between racist attitudes and how religious one is – that is if you consider Charedim to be more religious than modern Orthodox Jews. Which is certainly how they think of themselves.However, he does not think that Judaism is what teaches this racism because Judaism teaches that "man is created in the image of God" (ever realize how it is more likely that God was created in the image of man?, but that is beside the point). And so he argues that racism is contrary to Judaism, any Jewish racist is not a true Jew.
But he never explains where this correlation comes from. You cannot blame him for not doing so because he most likely explained where he thinks it comes from many times on his blog and does not want to explain it all over again. However, it is clear that his stance is that Judaism had nothing to do with teaching racism, rather it was some other external factor that created this racism (perhaps the separation the exists between Hasidim and non-Jews is what causes the racism).
I disagree with him. Judaism does teach racism, very much so. One of the reasons why I left Judaism was because I found it to be extremely racist. Consider for instance the stories of the Tanach. God commands the Israelites to smite the Moabites, smite the Amalekites, smite the Heshbonites, smite the Bashanites, smite the Caananites, and the list goes on, the smiting never seems to end. Why does God command this? Because the Israelites are God's nation, other nations are inferior to God, and so the Israelites have a commandment from God to carry out such a genocide.
If you teach young children these stories (thank Science these events never actually taken place) then you fill their heads with a nationalistic superiority complex. They believe that they are greater than the nations of the world because they are the Israelites while the other nations of the world are inferior to them.
This is just the beginning of the racism that is found in Judaism. Just as in an infomercial, "wait, there is more!". Consider what Rashi says about Haam in parshas Noach. I discussed this before here. Jewish children learn that black people originated because Noach cursed one of his sons who turned black. Black people originated as descendants from a cursed man, and Noach cursed him to be, "a slave of slaves you shall become".
How can you possibly say that God treats everybody equally if he allows such nationalism and racism? And furthermore, how can you possibly continue to say that Judaism does not teach racism when any child who learns such stories would most likely develop racist ideas.
This is why I do not agree with the statement that Judaism teaches equality, that is just pure deception. The poster seems to suggest in an implicit manner that racism in Hasidish communities is not from Judaism itself but from the isolation that they create around themselves from the external world. If you say this then ask the obvious question, why do Hasidim wish to isolate themselves from the rest of the world? From Judaism. It was Judaism that taught them they that they need to distance themselves from the world and not intermingle with the Goyim.
The last thing that I wanted to mention is that modern day Judaism is very different from conventional old day Judaism. Modern Jews are not racists because they learned those values as modern liberal values. This is why they are not racists. They had to learn that racism is a bad thing from modern values. It is not something they learned in Judaism. Indeed, old day Judaism was just as racist as most people were back then. If you really suggest that Judaism is against racism then it should have been a light unto the nations and taught about the evils of racism. But it never happened. Jews of old day Judaism were just as racist as most other people were back then. It was only in the modern age when recognizing racism as evil developed. Modern Jews picked up on it and now claim that Judaism always was against racism. Well, if it was against racism then why were there no clear stance against racism in more traditional Judaism?