for that, let's bring in the executive editor of cnn politics, mark preston. mark, give us the rule book here. >> reporter: well, john, this certainly is christmas for political geeks like kate and yourself. here we are, we're just hours away right now. and on the stage, we're going to see 15 presidential candidates broken up into two separate groups. the first group starts at 6:00 p.m. eastern time. and in that group, we will see four candidates. these are candidates who didn't poll high enough to get into the main debate. and then at 8:00, it will be the main debate. 11 candidates. now, if there's a question directed by a moderator or one of our questioners, hugh hewitt, a conservative radio host, or our own dana bash, then that person has one minute to answer the question. if that person were to invoke someone's name on the stage, that person then would get 30 seconds. now, those sound like they're pretty strict rules. however, this is a debate. they're not here to give