Fox Business, which hosts tonight's debate in Milwaukee, promised in a commercial to highlight “the real debate about our economy and our future." That does not mean the moderators will go easy on the candidates. We explain:
  1. Will a smaller group make a difference?
    It will be the first Republican debate with fewer than 10 candidates onstage. By relegating Gov. Chris Christie and Mike Huckabee to the earlier "undercard" debate, Fox Business may have imposed at least an incremental measure of order.
  2. Do the details make Trump disappear?
    A pattern has emerged in the debates so far: When the discussion turns to the intricacies of policy matters, Trump ceases to be much of a presence. Given his real estate career, he could speak broadly about economic issues. But if Tuesday’s debate takes a turn toward details, will he fade into the background again? And how will the crowd respond if he attacks Ben Carson or Sen. Marco Rubio?
  3. Can Ben Carson cauterize the biographical questions?
    Questions about Carson's life story are dominating the race right now. Trump has not been shy about raising the subject and, given recent polls, has ample reason to go there. Carson would most likely respond by reprising his attacks on the news media, but many voters will be eager to see how he responds under a level of pressure he has yet to face.
  4. What happens when finances get personal?
    A similar issue confronts Sen. Marco Rubio, who has been facing renewed scrutiny over his use of a Florida Republican Party credit card. Rubio sought to settle those questions by releasing a series of credit card records. But Trump, again, could bring up the subject even if the moderators do not deem Rubio’s personal finances relevant. And Rubio’s reaction to any attacks could be revealing about how he would hold up if he survives deeper into the primary contest.
  5. Which Jeb Bush will show up?
    Given how poorly he fared at the CNBC debate, Bush knows he needs to step up in Milwaukee. He will try a new approach, but it's not clear that disregarding questions and offering talking points will be enough to lift his prospects. Bush may need to show a measure of authority and forcefulness that has often been lacking in his campaign — especially if he wants primary voters to give him a new look.
  6. Does Cruz keep holding his fire?
    Sen. Ted Cruz does not like attacking Republicans who are held in high esteem by grass-roots conservatives. But with the Iowa caucuses in less than 3 months, he may not be able to avoid jabbing at candidates like Carson and Trump, who both have supporters he would like. How Cruz contends with those 2 rivals may signal whether he is coming to the conclusion that he must be a party to their collapse.