Your debate primer: Immigration.
It's a topic we haven't heard much about in the last couple of weeks. But not tonight. The remaining 4 GOP contenders are in Arizona, and it's sure to come up in this latest debate. Rick Santorum spent part of this week playing up his immigrant roots... minutes after meeting with Joe Arpaio, the controversial Sheriff known for targeting and arresting Latinos, he believes are illegals. (The same sheriff under investigation for 'unconstitutional policing')
We asked our panel where the candidates really stand on this issue - and how it will play in a primary, and how it will play in a general election.