At 7:00pm, on Tuesday, Jan. 3rd, Iowans will gather in each of the state's 1,784 voting precincts to caucus.
They'll get together in homes, schools, churches or gyms to show their preference for a presidential candidate. But, the parties vote differently.
After a representatives of each candidate makes a presentation to the group, Republicans vote by ballot, or by a show of hands.
But, rather than voting right away, Democrats organize into candidate groups after the speeches. Candidates need 15% of each precinct to be "viable", and move on to the next round. Supporters, whose candidate group doesn't meet that 15% mark, are free to support another candidate who's still "viable."