The winner will set the course of America for years to come.
The more candidates that there are, the likelier it is that voters cannot come to a consensus on the best candidate.
The number of candidates in presidential primaries has skyrocketed since the 2016 election. Divisions inside political parties and easy ways for candidates to raise money are among the reasons why.
There has been much analysis on the rise of Donald Trump as the result of widespread social and economic unrest, but a look at the primaries shows it to be more of a quirk of the system.
Global audiences have heard of US election terms like the primaries, the conventions and the Electoral College. But the history and exact meaning of these terms remains a mystery to many.
This primary cycle, few incumbents in the House and Senate are fighting off extremist challengers. Is that because the top of the ticket is taking up all the air?
Even with free, private ballots, a quarter of us still end up voting for the 'wrong' presidential candidate. Here's how to make sure you vote for the one who best matches your beliefs and hopes.