Aaron Bastani

Hillary Clinton may have been the Democratic victor in Iowa last Monday, but the scale of Bernie Sanders’s achievement there was as significant as his win in New Hampshire last night. Clinton is not only a former secretary of state and first lady, but has vast resources at her disposal. Before Christmas, George Soros donated $6 million to her Super PAC, Priorities USA. That’s the equivalent of 228,000 Sanders supporters each donating $26.28, the average contribution his campaign has received so far.

Today’s by-election in Oldham West and Royton is the first real test for Jeremy Corbyn as Labour leader. Nigel Farage has said the results will be 'very, very tight', but a victory for Ukip is unlikely. They'll probably come a closer second than they did in May to the late Michael Meacher, but that says as much about the Tories' inexorable fall in England’s north as it does about the parliamentary opposition.

There were several surprises in George Osborne’s sixth autumn statement as chancellor of the exchequer, but the announcement that grabbed the headlines was the (temporary) reversal on cutting working tax credit. For some commentators, that volte face, and the chancellor’s performance more broadly, was a display of unparalleled acumen. Here was a politician, they purred, at the top of his game, an exponent of statesmanship who could seize the centre ground while almost issuing an apology. For others, including the shadow chancellor, John McDonnell, Osborne’s offer was a political capitulation of the first order, a premier cru bottlejob by a champagne charlie. The truth, unsurprisingly, is somewhere in between, but what shouldn’t be overlooked is Osborne’s ambition for the top job.

More than 150,000 people have joined the Labour Party since May’s defeat, a figure which exceeds the total membership of any other political party in the UK. Over 60,000 have joined since Jeremy Corbyn became leader, more than either the Liberal Democrats or Ukip can boast among their ranks. The composition of the party is changing too. The average age of the party membership fell by 11 years over the summer – from 53 to 42 – and more women than men joined. Something similar happened with the SNP after the independence referendum, when its membership, in a nation of only five million, surged beyond the 100,000 mark. There, too, new members were younger and most of them were women.

Upsets don’t come much bigger than Jeremy Corbyn winning the Labour party leadership, so it’s unsurprising that Sadiq Khan’s triumph over Tessa Jowell to be the party's candidate for London mayor has been overlooked. Londoners won’t go to the polls until next May, but the ballot will be a defining moment for the Corbyn project in opposition, and the first significant bellwether of the likelihood of a Labour government, of some kind, four years later.