It's not as if anyone expected the announcement of a debate moderated by Donald Trump to go without criticism. Trump flirted with a presidential bid for months (still is) and gave his all to legitimize the birther movement. Of course not everyone would be happy he'd be calling the shots at a Republican forum.
Ari Fleischer, former White House press secretary under President George W. Bush, is one of the critics. He called the debate hosted by conservative magazine Newsmax on Dec. 27 "an invitation to a circus," according to the New York Times
“Donald Trump risks making a carnival out of a serious presidential campaign,” Mr. Fleischer said. “I think this is an opportunity for a candidate to stand up. I don’t understand the fear of Donald Trump, politically. He doesn’t have a constituency or a following.”