Replacing Roger Ailes won't be easy, Cramer says

Fox may be in trouble if Ailes exits, Cramer says

Cramer said it is "stupid" for 21st Century Fox owners not to be worried if Fox News CEO Roger Ailes exits the company.

On Tuesday, Fox said the Ailes review is ongoing and that he is "still at work."

Cramer noted that Ailes' time with Fox News helped shape the network into what it is today.

"This is a man who decided what America watched," Cramer said Wednesday on "Squawk on the Street."

Cramer called Fox News a personally run empire, which makes it difficult to replace someone like Ailes. There are "no other Ailes," Cramer said.