Racists are cowards, and can only survive cowering under cover huddling and whispering with people they already know share their bullshit views. They gain very few converts there.
Every generation racists raise more children embarrassed of their parents. And then they die. The battle for hearts and minds is not won in the invisible dark. It is won in the light, incrementally, over lifetimes, over centuries.
It needs patience, but ultimately this: only truth can withstand the light of human reason.