Republican Debate 2 is tonight. Who needs a good performance?

With the field down one candidate after former Texas Governor Rick Perry's withdrawal, the second Republican debate will air on CNN tonight at 8 pm EDT (1:00 am UTC). It will use the same primary/secondary system that the FOX News debate used, with the primary debate include the same 10 who participated in the main event in August as well as Carly Fiorina. The secondary debate, which airs earlier tonight, will consist of Lindsey Graham, Bobby Jindal, George Pataki, and Rick Santorum. Former Virginia governor Jim Gilmore, though considered a major candidate, was not invited to the debate.

Who needs to show up? 

For me, this debate is a huge opportunity for retired neurosurgeon Ben Carson. He's only trailing Donald Trump by 4 percentage points in a recent CBS news poll and has appeared to surpass Jeb Bush in many polls. Carson's political views are the closest to Trump's in the rest of the field and he could shift some of the Trump supporters if he can show himself as a calmer version of Trump with equal political knowledge and power.

Ben Carson could benefit substantially from a strong debate

I think this debate is also important for lower-polling candidates like Mike Huckabee, Chris Christie, and Rand Paul to try to convince voters who don't know much about them that they are strong candidates. If they fail to do this in these next few debates, they could be out of the race before the primaries even start.