There is hard work ahead but Joe Biden and the Democrats are in a good position to take on Donald Trump

Joe Biden’s time has come. He has tried to be his party’s candidate for president of the United States twice before. The third time he was lucky, and the Democrats were fortunate too, in that, by accident as well as design, he is probably their best hope of defeating Donald Trump in November.

The urgent need to bring President Trump’s disordered administration to an end has united the Democrats. Even if they had held a physical convention, it would have been a disciplined affair. Bernie Sanders, Biden’s main rival for the nomination, has been more supportive of him than he ever was of Hillary Clinton four years ago.

As it was, the party’s virtual convention has allowed it to showcase its greatest assets in a low-key way – without the adulation, the hoopla and the ticker tape – well suited to winning over voters who chose Mr Trump last time but who now have their doubts.

Barack Obama, having held back from attacking Mr Trump directly for most of the past four years, held back no more. “I did hope, for the sake of our country, that Donald Trump might show some interest in taking the job seriously,” said the former president. “He never did.” The tone was sad and regretful rather than savage, which is more likely to have the doubters nodding along.

So polarised has American politics become, however, that Mr Obama is never likely to be the best persuader for those Rust Belt voters on whom Mr Trump would probably rely. But the candidate is well placed to win over those voters himself. He has a blue-collar appeal that Ms Clinton could never match. She lost the 2016 election in three states – Pennsylvania, Michigan and Wisconsin. Those are precisely the states where Mr Biden is strong.

If all this sounds too much like fighting the last war, Mr Biden has the advantage of fighting Mr Trump on his record, and not just his bluster. The four years of Mr Trump in the White House have also had some effect on the Republican Party. It was traumatised into quiescence when Mr Trump became the candidate last time; this time there is a small, brave and motivated minority who intend to try to save their party’s and their country’s honour.

One of the interesting features of the early campaign has been the Lincoln Project, a group of former Republicans opposed to Mr Trump who are advocating a vote for Mr Biden. George W Bush, Mitt Romney and Cindy McCain (John McCain’s widow) say they do not support Mr Trump’s re-election, and some if not all of them might end up endorsing Mr Biden before election day.

Mr Biden’s sheer longevity of service, including a great deal of bipartisan work in Congress, makes it easier for Republicans to back him. He chose a running mate in Kamala Harris who is a known quantity. Everything about the Biden campaign is crafted to stabilise, to reassure and to build bridges. There is hard work ahead, but the way forward is clear.

We do not expect Mr Trump’s supporters to pay much attention to the indictment yesterday of Steve Bannon, the president’s former adviser, on fraud charges. And of course Mr Bannon is innocent unless he is proven guilty, but so many of Mr Trump’s associates have got themselves into difficulty with the law that they make the case among Democratic and independent voters against a chaotic and corrupt administration.

With a Democratic Party looking more united, Mr Biden is in a good position to take on a president who has used the office, in Mr Obama’s words, as “one more reality show he can use to get the attention he craves”.