How Many States Have Caucuses?

Donald Trump won the South Carolina Republican primary this weekend, and he and Florida Senator Marco Rubio are preparing to face off in the Nevada Republican caucus on Tuesday. Meanwhile, Hillary Clinton won the Nevada Democratic caucus So what's the difference between a caucus and a primary, and what do you need to know about Tuesday's events? We've broken it all down below — as well as what's at stake for the GOP presidential candidates this week.The Iowa caucuses — which Ted Cruz and Hillary Clinton won earlier this month — get most of the attention, but other states' caucuses are also important in the primary races. Much like primaries, caucuses decide how many delegates candidates get in future conventions, based on how many votes they get at the caucuses.All in all, 15 states and four territories including Iowa hold caucuses rather than primaries (although in some of these states, the party chooses whether to hold a caucus or a primary, so a state like Kentucky will have a Republican caucus and a Democratic primary). States holding a caucus include: Alaska, American Samoa, Colorado, Guam, Hawaii, Idaho (Democrats only), Iowa, Kansas, Kentucky (Republicans only), Maine, Minnesota, Nebraska (Democrats only), Nevada, North Dakota, North Mariana Islands, Utah, Virgin Islands, Washington, and Wyoming.