Why is 4chan/pol so obsessed with race?

Apart from it being full of alt-right paranoid maniacal incels, everything on that site (especially pol) is about complexion, eye color, hair color, and racial purity. For example, a person with 1/4 Italian or Portuguese ancestry is considered a "mutt" or "shitskin" and someone who's fully Anglo-Saxon or Scandinavian (especially with blonde hair, blue eyes and pink skin) is "based" or the "master race."

Also the "n" word is used constantly. The people even make up their own racial slurs.
Why is 4chan/pol so obsessed with race?
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