Good week: Joe Biden

The former vice-president cemented his lead over Bernie Sanders in the Democratic race with another string of primary victories on Tuesday – most significantly in Michigan, where the leftwing senator had sensationally beaten Hillary Clinton in 2016. Biden currently holds a lead of 881 delegates to Sanders’ 725 and the race moves next week to four states the Vermont socialist lost to Clinton last time: Arizona, Florida, Illinois and Ohio. If Biden wins the swing state of Florida, especially, it could be a knockout blow to Sanders in the race for the nomination. Belying his usual gaffe-prone image, Biden made a calm, statesmanlike speech on Super Tuesday election night praising Sanders and his supporters for their “tireless passion” and calling on them to help him defeat Donald Trump together. And he took the same measured tone on Thursday when he made a statement about the escalating coronavirus emergency – attempting to draw a contrast with the chaotic handling of the epidemic so far by the man he hopes to replace.

Bad week: Bernie Sanders

Facebook Twitter Pinterest Bernie Sanders: not ready to quit. Photograph: Charles Krupa/AP

Biden’s main challenger for the Democratic nomination was not ready to quit after his disappointing run of primary results on Tuesday. Although he was silent on election night itself, the next day Sanders made a forceful speech looking ahead to his debate with Biden on Sunday in Phoenix and insisting his campaign was “strongly winning” the contest of ideas. But the speech had a strange tone – it was almost as if Sanders was now preparing to move into a new role of holding Biden’s feet to the fire and making sure the left of the party is not crowded out by the moderate’s likely victory. “Joe, what are you going to do to end the absurdity of the United States of America being the only major country on earth where healthcare is not a human right?” Sanders asked. “Are you really going to veto a Medicare for All bill, if it is passed in Congress?” In 2016, his decision to stay in the race all the way to the bitter end – only endorsing Clinton in July of that year – was perceived by many of his supporters as helping push Clinton’s platform to the left, for example on healthcare. He may be trying something similar now. He made his own sober speech on the coronavirus.

Worse week: Donald Trump

Play Video 1:57 Trump's changing reactions to coronavirus: from calm to closing borders – video report

The president lurched this week from transparently playing down the threat of the coronavirus – it wasn’t long ago he was promising the number of cases “within a couple of days is going to be down to close to zero” – to full-on nativist crisis mode, closing the gates to most Europeans, with the exceptions, bizarrely, of the Brits and Irish. With over 1,600 cases in the US so far, this seemed to be a case of slamming the door to what he called the “foreign virus” well after the horse had bolted. And by falling back on the kind of ultra-nationalist authoritarian gestures that delight his base, Trump is risking the one thing most analysts agree would decimate his chances of victory in November: an economic crash. Wall Street plunged in the wake of his statement – which characteristically was littered with alarming factual errors that he and his administration had to rush to correct. If this was Trump taking charge in an emergency, few seemed reassured.

Worst week: Republicans

Facebook Twitter Pinterest Brad Parscale, Trump’s throws Make America Great Again hats to the audience before a rally in Michigan last year. Photograph: Paul Sancya/AP

Things were pretty bad for continental Europeans, suddenly barred from travelling to the US and abruptly blamed for the coronavirus by Trump. But surely the biggest losers of the week were Republicans – whose unswerving loyalty to their president may actually now be risking their health. A Reuters/Ipsos poll not only found Democrats to be about twice as likely as Republicans to say the coronavirus poses an “imminent threat to the United States” but also that “more Democrats than Republicans say they are taking steps to be prepared, including washing their hands more often or limiting their travel plans”. As if to illustrate this gulf, while Biden and Sanders cancelled rallies because of coronavirus fears this week, Trump pushed ahead with scheduling a new one in Milwaukee for 19 March. “While public health experts caution us against large gatherings, the commander-in-chief schedules a rally,” tweeted David Axelrod, former chief strategist for Barack Obama. “What message does that send?” As the coronavirus pandemic intensified further day by day, the rally was postponed.