The rationale I'm reading from this author and commenters is truly astounding. 

Gays and blacks feel the need to protest their historically documented abusive and non-constitutional  treatment at the hands of police. That is their democratic and constitutionally protected right.

And these commenters are saying, they have no right to protest, and police should now react with retribution by violating their oath to the constitution...again....by withholding policing services, for being excluded from the parade in  protest against this protest move.

All police have to do is, acknowledge their on-going legacy in this regard, apologize for their violations of the constitution, make retribution, and present a go -forward plan to drop the bigotry against gays, blacks and women.  

It's simple really...do the job you're to do as a public servant in the first place.