People wait in line to vote on October 15, 2020, in Raleigh, North Carolina.
CNN  — 

There are a number of states that could prove to be pivotal in the presidential election. Likewise, there are a number of states that could prove to be pivotal in the fight for Senate control.

There are, however, few states that could be informative of the ultimate outcome for both.

That’s why North Carolina is arguably the most important state to watch on election night, if you want to know which side is winning and which side is losing.

The state has become a key battleground and features a close presidential matchup between President Donald Trump and former Vice President Joe Biden. North Carolina also has a tight Senate race between Republican Sen. Thom Tillis and Democrat Cal Cunningham.

And Trump continues to focus on the state as he heads there Wednesday for a campaign rally.

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Presidential races have been tight in North Carolina over the last three cycles. No party has won the state by more than 4 points. Barack Obama won it by less than a point in 2008. Mitt Romney took it by 2 points in 2012. And Trump won it by a little less than 4 points in 2016, making it one of only six states Trump won by less than 5 points in 2016.

But unlike a lot of other important swing states, North Carolina has a history of voters casting a lot of ballots early. The state allows those early votes to be processed before Election Day, so it shouldn’t take days to count much of the vote. We’re not talking about Pennsylvania or Wisconsin, two states that are expecting a wave of absentee voters because of the coronavirus pandemic and have no real experience counting a lot of early votes.

The state does allow votes postmarked by Election Day to be counted, even if they arrive after polls close. Those votes, however, are likely to make up less than 10% of the total pool of voters.

In other words, unless the race is really close (which it could be), North Carolina should give us a fairly good insight into both the presidential and Senate landscapes on Election Night.

Right now, Biden holds a nominal advantage in the average of polls. Depending on what average you look at, he’s up by 2 to 3 points.

A Biden win in North Carolina would probably end Trump’s chance of taking the Electoral College. According to statistical models from the folks at FiveThirtyEight and Jack Kersting, Biden’s chance of winning the election when carrying the Tar Heel state is north of 95%.

In other words, the state is probably a must win for Trump. The reason is pretty simple: other swing states such as Michigan, Pennsylvania and Wisconsin are more Democratic leaning than North Carolina. If Trump loses North Carolina, there’s only the slimmest of hopes that he’s going to win other places that are less hospitable to him.

On the other hand, there are a lot of maps where Biden can conceivably win without North Carolina. He’s polling about 5 points better in Michigan, Pennsylvania and Wisconsin than North Carolina, for example. Winning those states, along with the states Hillay Clinton won four years ago, would get Biden to north of 270 electoral votes.

A Trump win in North Carolina merely means that Biden’s unlikely to blow Trump completely out of the water. We’ll have to see what other states show before having a clear understanding of the electoral landscape.

The state is even more consequential in the battle for Senate control. Democrats need a net gain of 3 seats, if Biden wins the presidency (allowing Kamala Harris to break the tie as vice president). Democrats look likely to lose in Alabama, so they’ll need to pick up four Republican-held seats to get to a net gain of 3.

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When you line up the different Republican seats in terms of their polling averages, Democrats look like they’re in the best shape in Colorado, Arizona and Maine. They have 5-point or greater leads in all of these contests. That leaves them with one seat they need to gain a majority.

At this point, the seat that looks most likely to put Democrats over the top is North Carolina. Cunningham, the Democrat, has an average advantage of about 4 points in the polls over Tillis.

Now, Democrats do have other paths to get to a majority without winning North Carolina. They are ahead in Iowa and are quite close in a large number of seats including the Georgia regular and special elections. The prospect just becomes dicier for them without North Carolina.

So just like in the presidential race, North Carolina could give us a keen insight into whether it’s going to mostly be an Election Day or an Election Week to know who has taken the Senate. No other state can really say that when it comes to both the presidential and Senate side of the ledger.