Because that's the real danger Americans face.
This from the president who hasn't mentioned, even once, the white supremacist who mowed down half a dozen people in a mosque in Quebec last week. But then the white supremacist is a big fan of Trump's so he figures he must be doing something right.
I'm just going to run this one more time:
It's nothing more than racist fearmongering. He's looking for a war against Muslims, here and abroad. And he'll be happy to start persecuting Mexicans and incarcerating millions more African Americans to keep "us" "safe."