In a scorching letter, Cuban American healthcare billionaire Mike Fernández is urging Cuban American Republican leaders from Miami to stand up to President Donald Trump’s immigration crackdown and speak up or “make room for others who can.”

“If you can’t find your voice at this moment, or tell the difference between one dictator and another, then perhaps it is time to make room for others who can and have a vision that you may lack,” Fernández told Secretary of State Marco Rubio and Miami U.S. Reps. Mario Díaz-Balart, María Elvira Salazar and Carlos Giménez in an open letter. He sent a version of the letter to each of them individually on Monday.

In the letter, Fernández, a deep-pocketed Coral Gables political donor, said Trump has adopted “a posture of cruelty” towards immigrants and accused the four politicians of having betrayed the communities they represent by staying silent.

“I know what it means to flee tyranny,” he said. “Like you, I carry that history in my bones and that pain in my heart. But like a growing number in our community, I have watched with dismay as the very values we once found sanctuary in are now being attacked by a previously unthinkable threat — the sitting President of the United States.

“In the face of all of this, the silence from our own leaders — the sons and daughters of exiles — has become deafening,” he added. “That silence is not neutrality, nor ignorance, it is complicity and cowardice… Your silence has caused fear and real harm to many in our community, in your districts.”