"Wow, Kristol really got mad at Juan for what he called a smear on Alito. Juan said basically that Alito was always for business and against minorities. Bill says there is no evidence of that at all."
One thing about being a Judge. You must (normally) justify your position on the ruling.
An appeals judge weighs the arguments of the two sides as posed in briefs and oral arguments. These are posed in the relevant laws and my offer arguments as to why they fail the tests. He then weighs those against the law and makes a ruling.