You would be targeting Caucasians and Asians simply because of their race. There would be no other reason to stop and frisk more whites other than their race.
His point stands though... if 1 in 10 white guys are committing murder and 5 in 10 blacks are, they should be stopping 5 black guys for every 1 white guy.
Im sure if the situation was reversed and 5 white guys were being stopped for every 1 black due to whites committing murder on a 5:1 basis, youd think it was perfectly fine, and no one would complain. (As it should be)