How are candidates chosen?

In a presidential election both the main parties - Republicans and Democrats - have to pick who they want to be president.

If the president has only served a single term (four years), then they are normally chosen by their party to stand for the job again.

But otherwise, the political parties choose who they want to represent them in the presidential election by holding things called primaries, which are votes in each state.

The primaries happen months before the big election, and the first state to vote is always New Hampshire.

But people don't vote for who they want to be president, they vote for the delegates that are supporting the person they want to be president.

Each state has a certain number of delegates, and the more people that live in a state, the more delegates the state gets.

If a candidate wins a state they get all that state's delegates.

Next, all the delegates go to a huge meeting called a national convention, which is held before the presidential election.

The candidate from each party with the most delegates then challenges for the presidency.

But some states don't pick their delegates in primaries. Instead they have special meetings for members of each political parties called caucuses.

The people at those meetings decide who the delegates will vote for.