As we explain in our guide to the US elections (which you can find a link to in the “In Depth” section at the top of the page), the winning candidate in Tuesday’s election must win at least 270 of the 538 available elections . university votes.

Steve Kornacki and Kristen Welker, political correspondents for our US partner network NBC News, examined Kamala Harris and Donald Trump’s most likely paths to victory – as well as some more unusual or chaotic combinations.

Remember: In the seven key battleground states of Arizona, Georgia, Michigan, Nevada, North Carolina, Pennsylvania and Wisconsin, Joe Biden’s biggest victory in 2020 was by less than 2.8 percentage points in Michigan.

Mr. Trump’s biggest (and only) victory was by less than 1.4 points in North Carolina. Little separated these states last time, which could lead to some unusual trends and combinations this time around.

Harris’ Direct Path: Across the Great Lakes

Pennsylvania, Michigan, and Wisconsin have all voted the same way in every election since 1992 — and every time except one (2016) it was for the Democrat.

Even before Ms. Harris replaced Mr. Biden, polls showed the Democratic candidate faring better in those three states than in the Sun Belt battlegrounds.

This is partly because Mr. Trump’s gains in polls this year have come from younger, non-white (especially Hispanic) voters, who are fewer in those states.

All Ms. Harris needs to do is maintain this trio (and avoid any surprises elsewhere) and she will get the 270 electoral votes she needs.

Trump’s direct route: through the Sun Belt

For most of this year, Mr. Trump has been stronger in Georgia and Arizona than in northern battleground states.

This is due in part to the gains he has made among non-white voters, particularly young Latinos. Since entering the race, Ms. Harris has gained ground with these voters, potentially paving her own path to the Sun Belt.

Yet it would take very little for Mr. Trump to flip Georgia (he lost by just under 12,000 votes in 2020) and Arizona (the margin was just over 10,000 last time). .

If he does that (and doesn’t have a problem in North Carolina), then all he would need is one of the states of Wisconsin, Michigan, and Pennsylvania.

Of those three, the closest in 2020 was Wisconsin, which Mr. Trump lost by about 20,000 votes.

More unusual scenarios: Can Trump win without North Carolina?

North Carolina is the only state of the seven major battlegrounds that Mr. Trump actually won in 2020 – but he won by just 1 percentage point. The Trump campaign increased its spending in North Carolina after Ms. Harris came in first.

Yet in the event Mr. Trump fails and Ms. Harris becomes the first Democrat since 2008 to win the state, Mr. Trump would still have a path to victory.

This path would involve Mr. Trump tearing down the “blue wall” and taking all of Pennsylvania, Michigan and Wisconsin, as he did in 2016. This would mean that the seven key battleground states would not would not point in the same direction, since Mr. Biden won. Pennsylvania, Michigan and Wisconsin in 2020 while losing North Carolina.

Second, even if Mr. Trump wins these three states, he would still need to win either Arizona or Georgia to achieve a victory without North Carolina.

More unusual scenarios: Can Harris win without Pennsylvania?

A significant development since Ms. Harris replaced Mr. Biden as Democratic leader has been the party’s improving prospects in the Sun Belt states of Arizona, Georgia, Nevada and South Carolina. North.

And this expanded Democratic map gives Ms. Harris the chance to get 270 electoral votes even if she loses in the Great Lakes states.

Let’s look at a scenario in which Mr. Trump wins in both Michigan (15 electoral votes) and Pennsylvania (19 electoral votes), where the poll results remain close.

Ms. Harris can still surpass 270 electoral votes by winning Georgia (16 electoral votes), Nevada (6 electoral votes) and North Carolina (16 electoral votes).

Or let’s say Ms. Harris also loses Nevada. She can still make up for it by winning Arizona and its 11 electoral votes. Again, this scenario would rely on states moving in opposite directions compared to 2020.

But since they were so closely grouped then, who’s to say that the populations haven’t changed enough to create an unusual situation?