Final answer:
The United States president is elected through the Electoral College, which consists of electors from each state and the District of Columbia. Electors vote on behalf of their party, but the winner of the popular vote may not always win the Electoral College.
Step-by-step explanation:
The president of the United States is elected through the Electoral College, a system of electors the number of which is equal to the total number of Senators and House members, plus electors from Washington, DC.
Each state is a district. States choose electors using different methods including state conventions, state party central committees, appointment by state governors, state primary, or nomination by the party's candidate.
Electors are expected to vote on behalf of their party and according to the popular vote. However, as we have seen in recent elections, the winner of the popular vote is not always the winner of the Electoral College.