"can you dig it" is also the same thing as "can you roll with it" or "do you find it acceptable". basically, meaning if one can agree with a certain thing.
In the Plessy v. Ferguson case, the Supreme Court's ruling of the "separate but equal" law being constitutional was problematic because the "separate but equal" law accepted segregation and the discrimination that were against blacks.
Hope this helps!
If you are writing an Argumentative Essay, a counterclaim is a claim that acknowledges the opponent's claim, and proves your point further.