The fourth Republican debate will air at 9 pm Eastern tonight on the Fox Business Network. Here's what you need to know. Full story:
  1. When: 9 pm Tuesday
  2. Where: Milwaukee Theater
  3. TV: Fox Business Network
  4. Online: At, a free live stream will be available
  5. Tonight's event will be the least crowded GOP debate yet — there will only be eight candidates on the primetime stage. Donald Trump and Ben Carson are neck and neck for the poll lead, so they'll be center stage.
    Marco Rubio and Ted Cruz, who got poll bounces after being declared the winners of the last debate, are currently in third and fourth. Jeb Bush, whose campaign has not been going well lately, is down in the fifth place spot. And rounding out the lineup are Carly Fiorina (who's lost most of the poll bounce she got from previous debate performances), John Kasich, and Rand Paul.
  6. The earlier undercard debate will begin at 7 pm EST. The recent undercard debates have generally been unmemorable, but this one has a different lineup: Mike Huckabee, Chris Christie, Bobby Jindal, and Rick Santorum. Huckabee and Christie will be in the undercard for the first time after failing to meet the polling cutoff for the primetime event.
    And usual undercard participants Lindsey Graham and George Pataki have been dropped for failing to reach 1 percent in any of the four most recent national polls — they'll join Jim Gilmore in no-man's-land.