It's not just CNN. Pretty much all the debates are the same. Trump sits front and center and is always given the last word. And Trump always gets the last word when someone attacks him. Conversely, if Cruz is attacked the moderators shut him down in responding and moves on.
I think Trump is there just to prevent Cruz from winning. After all, Trump is a life long Dim who sung the praises of Hillary Clinton as early as 2013. And if it were not from Trump, Cruz would be winning.
Look its on Cruz to take the front runner spot away from Trump. If Cruz can't even beat a guy like Trump or dispatch the wet behind the ears Rubio damn how is he going to beat Hillary and the entire MSM in the general? Cruz with his education and resume should have mopped the floor with these guys but he failed, facts are facts. Now he's fallen back to desperation tactics that play right into the stereotype people have painted for him.
Nobody lofted Trump into the front runner spot, he went out there and took it. He took some risks, he took some tough positions, he kicked some ass and grabbed it. Then defended it against not only his opponents but the GOP establishment and the MSM and some debate moderators with questionable motives. You can tell he's used to winning and knows how.