I believe that you, like most Americans, conflate social license with civil rights.    A civil right is about the relationship between the individual and the government.   I can exercise my civil right to freedom of speech and it means that the government, at ALL levels of government in the US, cannot arrest or prosecute me, or confiscate my property for exercising my right.     An American's right to free speech, however, is not a social license.  It doesn't mean there will be no social consequences to what we say or write.    We can be criticized, divorced, evicted from the store, the job, the park, etc., for the things we say and write.  But the government still can't arrest us.

You falsely equate Mr. Kaepernick's act of protesting undeniable racial injustice that still exists for many Americans, with you having the freedom to criticize him for his act of protest, and you're only half correct.  Yes, you can criticize Mr. Kaepernick and we won't call the police or the military.