A new CBS News/New York Times poll shows the popular vote for president is tightening. Hillary Clinton leads Donald Trump by three points, down from her nine-point lead in the previous poll. But the Electoral College is what elects the president, state by state.

Recent polling shows Clinton and Trump neck-and-neck in crucial swing states like Florida, North Carolina and Nevada, and Clinton with slim leads in Wisconsin and Pennsylvania.

CBS News Elections Director Anthony Salvanto says that although the race is tightening, Donald Trump still has a lot of work ahead of him in the last five days to reach the necessary 270 electoral votes to win the election.

Watch the video above for more of Salvanto’s analysis on the must-win states that will decide the White House.