Story highlights Haroon Moghul: Trump is quick to tweet denunciations on news of any attack by Muslims. But after an attack on Muslims, he is silent

He says Trump and supporters have excused extremist language from the right, seeming to indicate that violence against Muslims doesn't matter

Haroon Moghul is a senior fellow at the Center for Global Policy. He is the author of the new book "How to be a Muslim." The views expressed are his own.

(CNN) For a long time, a lot of Muslims had their heads in the sand when it came to jihadist violence. They preferred to pretend as if it did not exist, or that foreign policy was solely to blame.

We've come a long way. We've learned that radicalization is a thing, and that we have a responsibility -- if we love our religion and our communities -- to think about what we can do to produce a different future for Islam and for Muslims. To change how our religion is taught in some spaces and some places.

Donald Trump and his supporters are going to have to make the same journey. They've excused, or even encouraged, extremist language and rhetoric for a long time now, and, well, here we are today, with a President who pretends that violence against Muslims doesn't matter.

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On Sunday night, I was delivering a book reading at a Muslim cultural center in Florida and was asked to speak directly to the young Muslims in the room, to share my own experiences and struggles growing up as an American Muslim.

The truth is, my experiences and theirs are very different. When I was growing up, Islamophobia wasn't much of a thing. Maybe my friends and colleagues thought I was a little different, my name slightly harder to pronounce, but I never encountered overt hostility. These kids, though, they're growing up in a different world.