Dr Rebecca Stone, Associate Professor of US Political History from The University of Warwick, said: "In every American election in history where the incumbent of the governing party has chosen not to run, the opposition has won. A more similar comparison, however, might be the election of 1856 – another era of extreme division in US history. The candidacy of incumbent President Franklin Pierce was rejected by his own party at the Convention, but their new nominee, James Buchanan, won comfortably that November."

President Joe Biden withdrawing from his campaign for re-election opens up the Democratic nomination at a crucial time in the election calendar. There are four weeks until the Democratic National Convention where the party will confirm their candidate for the presidency. It's important for the Democrats to show unity now and not descend into a period of damaging in-fighting, so it seems highly likely they will select Vice President Kamala Harris who Biden and other senior Democrats have already endorsed.

The tragic death of Tori Bowie is another call for more to be done to tackle the high rate of maternal morbidity and mortality among Black women. As highlighted by Allyson Felix, three out of four American team-mates at the Rio 2016 Olympics either died or nearly died due to pregnancy. There are other high-profile Black women with similar stories. These are examples of how the risk goes beyond socioeconomic class. The racial inequities in maternal health is a global issue.

"Usually by a couple of days into the counts you do have a clear idea of which candidate will win which states. This year it’s much more difficult to call because of the time it’s taking to get through some of these really quite substantial numbers of ballots, of postal votes especially, in some of the crucial states - so we don’t yet have either candidate at the magical 270 Electoral College votes needed for a win."

"The courts could again be crucial in settling the contests this year, not only in Florida but in other swing states if the voting margins are very close. With Trump and Senate Republicans having successfully tipped the balance to conservatives on the Supreme Court, newly appointed Justice Amy Coney Barrett could prove a significant character in this year's election battle."