US election polls tracker: who is leading in swing states, Trump or Biden?

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 to track how the race is developing in the areas that could decide the election, six of the eight states we focused on were those that flipped to Trump​ in 2016 after backing Barack Obama in 2012. Arizona and North Carolina were also added due to what they might tell us about a shifting electoral landscape – they could emerge as vital new swing states this year.

We must caution that the polls – particularly some swing state polls – severely undercounted Trump supporters in 2016. We are not certain, despite assurances, that they they have corrected this​. Additionally, they may be over-counting Democratic support (more people may say they will vote for Biden than actually turn out).

We present the latest polls with those caveats in mind.

The national polls

The latest polling average puts Biden ahead of Trump nationally.

While the national poll tracker is a poor indicator of how the crucial swing states will sway the election, a strong polling lead across the country can point to how the race will develop.

Each day, the Guardian’s national poll tracker takes a 14-day average of national voting intention polls.

On Tuesday 3 November 2020, Americans will vote for their next president, with a choice between ​Donald Trump, the Republican incumbent, or his Democratic challenger, Joe Biden.

Methodology

The Guardian poll tracker tracks the latest polls in eight crucial swing states. For Biden to win, he needs to reclaim some of these swing states.

The Guardian is collating polls in each of these ​states, as well as another set of national polls. Polls are assessed for their reliability by looking at factors such as their sample size.

Our polling average is a 14-day rolling average: on any day, we collate any polls published in the last 14 days and take a mean average of their results.

If any ​company ​has conducted multiple polls in the last 14 days, we average out their polling results in order to give them just one entry. After this standardi​zation process, we take a mean average of these daily entries to present the polling average.

• This article was amended on 28 October 2020 to clarify that Maine and Nebraska are alone in assigning their electoral college votes in proportion to the popular vote.