With all eyes on the Republicans, a reminder of the state of play for the Democrats.

Despite calls for him to step aside, Joe Biden is expected to receive the official presidential nomination from fellow Democrats - according to four sources cited by Reuters.

Democrats and Republicans typically use their national conventions to officially nominate their candidates, but Mr Biden will be nominated weeks before his party gathers in Chicago on 19 August.

This was a plan announced long before the president's shaky 27 June debate, with a virtual vote planned for late July.

Biden campaign officials said they expect Saturday's assassination attempt on Trump will reduce the pressure on him to step aside.

Mr Biden, 81, has repeatedly insisted he is not going anywhere and says he is best equipped to beat Trump.

Why is there an early vote?

The early nomination was scheduled to deal with an Ohio law that could have kept Mr Biden off ballots in the state if he weren't nominated by 7 August, before the convention.

Democrats are still moving forward with the plan even though Ohio's governor signed a bill in May to secure Mr Biden's spot on the state's ballot.

An online or virtual vote means no chance of a live convention floor battle in Chicago that could embarrass Mr Biden and throw the campaign into chaos.

In any case, there does not appear to be any well-defined push to rally delegates around any other candidate ahead of the virtual vote, Reuters reports.

How will the vote work?

Many of the details will be decided on 19 and 21 July, when the party's convention rules and credentials committee meet.

Any virtual process is likely to happen within days of those meetings, according to officials.

What if Joe Biden steps down after he is nominated?

If Mr Biden steps down after the official nomination, then the 435 members of the Democratic National Committee would hold a special session to choose a new candidate.

The members are divided roughly equally between men and women as well as various constituency groups including LGBT+ representatives and racial minorities.