George Zimmerman didn't happen by accident. He happened in context. The context is racism. Racism derives from race.
The remedy is eliminate race. To do that you need law.
The needed law that requires every Homo Sapien female's first-born be fathered by either ordinary copulation or artificial insemination from or by a male of another race.
Then racism gets defeated in the innate god sponsored crucible of mother-love and sibling support.
Then you establish a law stipulating that only persons of mixed race DNA be permitted to hold public office. I'd further stipulate that all elected names go into a hat, and get to represent any state except the one which elected them.
Except, of course, for Texas. There's something in Texas water that addles the brain. So I'd spend half the military budget to find a vaccine for addled. Perhaps one would need to quarantine or sequester tea drinking Evangelistic types by one residential fenced area, say the Texas panhandle. With Karl Rove in charge until the addle they can't handle does them in.
Then I'd take half the military budget to build decent schools as places to learn without regimental paper work impeding the process and taking all the fun out of it.
(I learned more breaking into my District 99 one-room school summer vacation than teachers taught me -- and I always put the books away and washed the blackboard.)