Presidential elections in the U.S. aren't decided by popular vote. They are instead determined by the Electoral College. Here's how it works.

Find the latest election results for president, state and local races on KSAT.com. It all comes down to this. A presidential campaign unlike any other ends on Tuesday. In a deeply divided nation, the election is a true toss-up between Democrat Kamala Harris and Republican Donald Trump.

In 2016, Trump won by squeezing out just enough votes in key Electoral College states over Democratic rival Hillary Clinton, with the race being decided by about 77,000 votes. Then, in 2020, President Joe Biden eked out a victory over Trump so close that it took days to call.

The Electoral College is how the president of the United States is elected. In the U.S., there are 538 votes up for grabs between all 50 states and the District of Columbia. To win the election, a candidate needs to secure 270 electoral votes which is the majority of the College.