Disincentivizing white supremacists

Paraphrasing another DU writer:
"Don't underestimate the depravity of the average trump supporter. Today, they are quietly happy and proud because yesterday their President issued a shrouded threat of violence and today on the other side of the world his devotees carried out on that threat. "

So, what to do about it?

We know what they hate, migrants and refugees "invading" their "homelands'. Why not tie the numbers of newcomers to incidents of hate. Let them know that every swastika painted on a synagogue will raise the refugee limits by a hundred. Every immigrant slaughtered by these terrorists will raise the refugee quota by a thousand.
Would the Christchurch murderer become a hero to the white supremacists if his horrific acts became directly responsible for an additional 50,000 refugees being allowed into NZ? I suspect it would change their thinking?