Joe Biden is leading ​Donald Trump in the national polls for the presidential election.

But that doesn’t guarantee ​the Democratic candidate victory. Hillary Clinton also had a clear lead over Trump in the polls for almost the entire 2016 campaign. She ended up losing in the electoral college.

​Because the presidential ​voting system assigns each state a number of electoral college votes, which​ go to the state’s victor regardless of the​ margin of victory (with the exception of Nebraska and Maine), a handful of swing states will ​probably decide the election and be targeted heavily by campaigners.

Each day, the Guardian’s poll tracker takes a rolling 14-day average of the polls in ​eight swing states.

In order