WASHINGTON (AP) — A major misconception about the vote for U.S. president is that it is a national election. It’s not.

Instead, it consists of 51 elections — one in each state and in the District of Columbia. And that’s more than a technical difference.

The states conduct all elections and decide who is eligible to vote, beyond the bare requirements of being 18 years old and a citizen, set by the U.S. Constitution. For example, convicted felons can vote in some states, but not in others.

And the national vote tally is irrelevant to picking a president; what matters is the selection of representatives from each state to the Electoral College.

Each state chooses electors (their number set according to the number of men and women it sends to Congress) sworn to vote for the candidate who won the most votes. The electors meet in January to choose the president.

In most states, winner takes all, meaning that if Candidate A earns just one more vote than Candidate B, Candidate A wins all the state’s electors.

But Maine and Nebraska do it differently. There, two electors are chosen by statewide vote, and one is chosen from each congressional district. So for example, Maine split its vote in 2016: Hillary Clinton won the two at-large electors and one district, while the other district went for Donald Trump.

While losing the national popular vote, a candidate can rack up electors by winning small states, or by winning by small margins in large states. This is what happened in 2016, when Clinton won the popular vote by nearly 2.8 million votes while Trump won the Electoral College, 304-227.

While that outcome might seem inadvertent, the system itself is not an accident. The framers of the Constitution embraced federalism — meaning while they wanted a functional federal government, they sought to balance that by preserving the powers of the states. One way they sought to ensure that was by putting elections in the hands of the states.