Now that Biden is back in the race, Super Tuesday will play a huge role in deciding Trump’s election opponent

Editorial: With more than a dozen states making their choice for the Democrat presidential nominee on one day, the stakes are high

The race appears to be narrowing to Sanders and Biden (Getty)

Joe Biden was always expected to do well in the South Carolina Democratic primary, but the sheer scale of his victory there – by more than two to one over his nearest rival, Bernie Sanders – is important. It means that as we approach Super Tuesday, where 14 states will vote, a clearer idea of the shape of the presidential election in November is forming.

First, South Carolina shows that it is far too early to write off Mr Biden, a doughty and determined campaigner, if a sometimes forgetful speaker. Mr Biden makes a claim, as a former vice president to Barack Obama, that he enjoys especially strong support among black voters, something that would pay a dividend as soon as the southern states start to come into play. The impressive result in South Carolina would seem to verify that, but also that Mr Biden could build the kind of broad coalition needed to wrest the presidency from Donald Trump, in what will be an unusually brutal contest later this year.

The second lesson is that the Democrat race seems to be narrowing sharply down to Mr Biden and Mr Sanders, given Mr Sanders’ previous relatively strong showing in Nevada, Iowa and New Hampshire. Thus far, Mr Sanders leads on delegates selected for the summer Democratic convention to choose a candidate; Mr Biden is ahead on the popular vote behind those delegate selections. Both are narrow leads, but they are pushing out the others. Tom Steyer, a billionaire hedge fund manager, has pulled out of the Democratic race, as well as Pete Buttigieg. Elizabeth Warren and Amy Klobuchar, previously prominent, look to be running out of road. The rest of the Democratic hopefuls have secured their places in the footnotes of history, or else laid a marker down for the future.

The exception to that is of course Michael Bloomberg, who has sat out the previous primaries and caucuses and is relying on Super Tuesday (and a free-spending campaign) to disrupt the Biden-Sanders duopoly.

Around a third of the delegates are up for grabs on Tuesday, including those from Texas, California and North Carolina. It is an opportunity for the best-placed candidates to pull ahead. However, the so-called 15 per cent rule means that only those candidates who reach that threshold of the popular vote in primary elections can pick up delegates.

That should eliminate the long tail of minor runners. However, it could also, paradoxically, strengthen some of the middle-ranking surviving candidates – including Mr Bloomberg and Ms Warren. That would mean another few months of Democratic wrangling, making it that much harder to organise against the campaign to re-elect Donald Trump.

So the Democratic race remains open and somewhat unpredictable, but, most likely the party will by the summer be presented with a choice between Mr Sanders, a self-styled democratic socialist who went to the Soviet Union for his honeymoon; or the more conventionally triangulating former vice president Mr Biden, who was in the White House during the long wars in Iraq and Afghanistan.

The ideological divide on the Democrat side could scarcely be starker; but 2020 will not be a vintage year for diversity. This looks to be an election, bluntly, for old, white privileged men. A 77-year-old man from the centre left with 36 years in congress (Mr Biden) is taking on a 78-year-old man from the left with 29 years in congress (Mr Sanders) for the Democrat nomination. The winner will fight the 73-year-old Republican incumbent Mr Trump. Little wonder, then, that attention is also being paid to their respective running mates, with Michelle Obama’s name figuring in Democrat chatter.

The progress of America and the world in the 2020s depend vitally on the next few days in American politics. The world is watching, with some trepidation, and wondering quite how the US got here.