What is a Caucus?

A caucus is a political gathering used to choose presidential frontrunners. Out of a bunch of Democratic and Republican candidates, each party has to narrow them down to one per side. Fifteen states use caucuses to pick their top presidential hopefuls. Then large, national party conventions will make the final choices, taking each state's vote into account. Those remaining two candidates will then face off in November and one will become the next President. Iowa's caucuses are traditionally the first in the nation.