From NBC's Chuck Todd
I'll be blogging from the control room. My job: listen for news, listen for surprising answers and make sure we follow our planned script of questions as closely as possible. With 20 minutes to go before show time, I can report that all the candidates showed up on time for wiring. They are backstage, ready to be brought on stage very soon.

The cameras roll at 7 p.m. ET.  Here's the format:

• 90 minutes, no commercial breaks
• No opening or closing statements
• 1 minute for each answer + possible 30-second rebuttal
• "Lightning round" at end with 30-second responses