Exactly what we know about who's going to win the US election.

There are 14 days until the US Presidential election, when Americans will decide if President Donald Trump will remain in the White House or be succeeded by Democratic Party nominee Joe Biden. Best known as Barack Obama's former vice-president, Biden is campaigning alongside his vice-presidential pick, Kamala Harris.

According to the polls, he has led a successful race. Both national and state polls show Biden as the winner of the November 3 election. 

But after the unexpected win of Donald Trump in 2016, against Hillary Clinton, can we even trust polls?

Watch: Donald Trump and Joe Biden in the first presidential debate. Post continues below. 

Here's everything we know about who will win, according to the experts. 

What do the national polls say?

National polls say Joe Biden is more popular that the incumbent, President Trump, suggesting he has more than 50 per cent of the vote. 

However, national polls are poor indicators for who will actually win.  

In 2016, Hillary Clinton won the popular vote by nearly three million votes. She didn't win, though, because she didn't garner enough Electoral College votes. Essentially, the American voting system means that even if a majority of Americans support Biden, it's more important how the supporters are spread across the country. 

"The national poll is all very interesting, but it means nothing," ABC Planet America's Chas Licciardello told Mamamia's daily news podcast The Quicky. 

"The state polls are the ones that count. No one gets a single position in the White House based on a national poll."

Listen to The Quicky, Mamamia's Daily news podcast, here. Post continues below. 

So, what do the state polls say?

Joe Biden is looking promising on the state polls. 

The majority of states in America tend to vote the same way in every election. For example, Utah has voted for the Republican nominee in every presidential election since 1964. 

This means presidential candidates will be won in the battleground states - also known as swing states. 

Key battleground states, which were won by Trump in 2016, include: Arizona, Michigan, Iowa, Wisconsin, Florida, North Carolina, Georgia and Pennsylvania. 

According to Licciardello, the three most important of these swing states will be Wisconsin, Michigan and Pennsylvania. 

In Wisconsin, Biden is ahead by about six or eight points according to a poll by The New York Times and Sienna College. Biden is also ahead by eight points in Michigan, and by about four points in Pennsylvania. 

"If Biden wins those three states, he wins the whole election," Licciardello explains. 

So - it looks promising for Biden. 

But weren't the polls wrong last time?

Yes. Which is, of course, why so many people are hesitant to believe the polls this year. But according to Licciardello, there's reason to believe that the polls will be more trustworthy this year.

"Biden is in a very different position now to what Clinton was because he's up against an incumbent. When Hillary was running in 2016, she was up against a fellow challenger," he explained. "The rules are very, very different between when there's an open race and when there's an incumbent."

The polls predict Joe Biden will win the presidential election on November 3. Image: Getty. 

The political analyst went on to explain this is because "people have already made up their mind one way or another how they feel about whether an incumbent should be returned to the presidency, whereas when there's no incumbent, they're still making up their minds about both of the challengers."

Licciardello added that while margins are similar, the numbers are higher, meaning there are less people who are undecided, and who could sway the vote last minute. 

"So if you're running against an incumbent and 52 per cent of people have decided that they don't like him, it's very hard to convince them to change their mind at the last second, from what they thought for the last four years, which is the case here with Joe Biden. He's passed 50 per cent in all these key states."

Plus, Licciardello isn't alone in thinking the polls will be more trustworthy this year. 

The New York Times polling analyst Nate Cohn also says the state polls will be more accurate in 2020 because there are less undecided voters. 

"At this point in 2016, about 20 per cent of voters either supported a minor-party candidate or said they were undecided," Cohn has explained. "Today, the number is about half that level."

Feature image: Getty.

Sign up for the "Mamamia Daily" newsletter. Get across the stories women are talking about today.