Last night, Biden limped in fifth having come fourth in Iowa. The next Primary, at the end of the month, is in South Carolina — where black voters make up a much bigger share of Democratic electorate than the mostly white states that have voted so far. As Barack Obama’s Vice President, Biden was expected to win in SC. But now, to arrest his backward momentum, he absolutely has to.

His job will be made harder because he has failed to unite the moderate wing of his party. Among the rival moderates there’s Mayor Pete (Buttigieg) who we’ve mentioned, and also Minnesota senator Amy Klobuchar, who finished a strong third in New Hampshire. Then there’s Tom Steyer — a billionaire activist who’s been pretty marginal in the race so far, but is splashing the cash in South Carolina.

As for the radical wing of the party, Sanders has only one serious rival and that’s Elizabeth Warren. She took a poor fourth in New Hampshire, winning no delegates (unlike in Iowa, where she did OK). However, she still beat Biden, so lives to fight another day. Sanders, despite his poll position, is only one health scare away from dropping out of the race — in which case Warren would be the best-placed candidate to inherit his voter base.

But as things stand, there is a field of five viable candidates who have all won delegates (i.e. to the Democratic convention where the nominee is chosen): Buttigieg, Sanders, Warren, Klobuchar and Biden. Also, let’s not forget Steyer and his pile of money — and, waiting further down the line, Mike Bloomberg and his even bigger pile of money. Bloomberg’s strategy is to let his rivals exhaust themselves in the early states, while he builds up support in the states that all vote on Super Tuesday (March 3rd).

So despite the early successes of Sanders and Buttigieg all the ingredients are in place for a deadlock in which no candidate establishes a commanding lead. If this leads to a brokered convention, just about anyone could emerge victorious.

Including Hillary Clinton.