Everything is decided by the “indecisive”
For centuries, the United States has had a two-stage election system. Its main feature is that voters do not vote for the president directly, but for the electors. It is these people who ultimately determine which candidate the state will vote for.
There are 538 electors in total, to win you need to enlist the support of 270. Each state has a different number of electors, it depends on the population. For example, California, the most populous state, has 55 electors, and from such sparsely populated states as Alaska, Vermont, Delaware, Wyoming, South and North Dakota, each candidate can receive only three votes. The winner-take-all rule applies almost everywhere. The exceptions are Maine and Nebraska, where electors can be divided into constituencies. Also, the District of Columbia, where the capital of the state, Washington, is located, enjoys a special privilege. It is not a state, but still has three electoral college votes.
In theory, electors should take into account the will of the voters and vote for the candidate who is supported by the majority of the population of the state – this is usually the case. Since the beginning of the last century, there were only 15 electors who refused to vote for a candidate approved by the voters. However, nothing prevents the electors from changing their minds – from a legal point of view, they have every right to do so. At the same time, the US Supreme Court allowed each state to independently decide whether or not to impose penalties for the so-called “wrong electors.” In any case, these sanctions are usually quite symbolic – for example, in Washington, the defected members of the college are fined a thousand dollars.