With one day left in the 2024 campaign, the polls show one of the closest presidential elections in the history of American politics.

Across the key battlegrounds collectively or nationwide, neither Kamala Harris nor Donald J. Trump leads by more than a single percentage point. Neither candidate holds a meaningful edge in enough states to win 270 electoral votes.

In the history of modern polling, there’s never been a race where the final polls showed such a close contest. If the poll averages are exactly right down to the decimal (they will not be), Ms. Harris would barely need to outperform the polls to prevail.

The 2004 election between John Kerry and George W. Bush might be the next closest election in terms of polling, but it’s hard to put it in quite the same tier. Even then, Mr. Bush was a modestly clear favorite. Mr. Kerry needed to win states like Florida and Ohio, where Mr. Bush held a consistent if narrow lead in the final polls.

This time, neither Mr. Trump nor Ms. Harris faces such a narrow path to victory. In the key tipping point state in this year’s pre-election polling — Pennsylvania — both candidates can point to several high-quality polls showing them tied or ahead. For good measure, they’re both highly competitive in additional states, should Pennsylvania fall through.