Hmmm...
J.R. says "Fight hate...", which sounds to my ear a bit contradictory~
Dear Lauren refers to it as "foiling", from the word 'foil' - a fencing sword~
The charming element of this form of protest is that it isn't fighting fire with fire, but rather quenching that fire (or at least limiting its spread) with humor~

"White Tower..."
"... mini-burgers!"

Burble Stonefeather

Just a few retorts that came to mind...
Their ugly slogan could easily be heard as:

Nazty Ks: "Wipe our... "
Classy Clowns: "...Snotty snouts!"
or:
Nazty Ks: "Wipe our ... !"
Classy Clowns: "Wipe your own... and potty train!"

and a few more - (Excuse the typo - I can't bring myself to actually write it out):
Nazty Ks: "Wite powr!"
Classy Clowns: "...For pink men?"

Nazty Ks: "Wite powr!"
Classy Clowns: "Dirty laundry!"

Nazty Ks: "Wite power!"
Classy Clowns: "...Holds the rainbow!"

L'oven quiches,
jeroboambramblejam