LIVE 6pm PST: Watch The YouTube Democratic Candidates Debate

The Democratic candidates are facing off for the fourth time on January 17, and it’s bound to be a volatile battle between the remaining three candidates.

8 Big Issues that will likely be discussed

  • The U.S.-Iran prisoner deal

  • Sanders’s general election viability

  • Benghazi and the ’13 Hours’ movie

  • National security

  • Islamic State and terrorism

  • Gun control

  • Climate change and energy

  • Clinton’s ties to Wall Street

Now, as Democrats get ready to debate for a fourth time, in South Carolina on Sunday — in the middle of a three-day holiday weekend — there are signs Clinton’s lead is evaporating. A Quinnipiac University poll out Tuesday shows her rival, Sen. Bernie Sanders (I-Vt.) ahead in Iowa by five points. A Selzer & Company poll showed Clinton up just two — down from wider previous leads.