Joe Biden ready to go head to head with Donald Trump in duel for the White House

Mr Biden will represent the Democratic Party against President Donald Trump this autumn, assuming there are no unexpected developments in what will be a contest between two men in their 70s.

Mr Biden will probably not secure the number of delegates needed to clinch the nomination until June.

But without any Democratic rivals left, a campaign that will almost certainly be the most expensive and among the nastiest in US history is under way and Mr Biden is now effectively the presumptive nominee for the party still licking its wounds after Mr Trump’s victory over Hillary Clinton in 2016, a result that stunned most pundits.

“It won’t be easy. Nobody’s confused about that. But we are ready for the general election. We are ready for our standard-bearer,” Democratic National Committee chairman Tom Perez said.

“I’m confident because Joe Biden’s values reflect the values of the majority of the American people that we can win.”

In Mr Biden and Mr Trump, voters will choose between two white septuagenarians with dramatically different prescriptions for health care, climate change, foreign policy and leadership in an era of extreme partisanship.

At 77, Mr Biden becomes the oldest major party presidential nominee in modern history.

And having spent most of his life as an elected official in Washington, no nominee has had more experience in government.

But in Mr Trump, Mr Biden is up against an adversary the likes of which he has never faced in his decades-long political career.

The 73-year-old Republican president opens with a massive cash advantage and a well-established willingness to win at any cost.

Mr Trump’s campaign is moving forward with a multi-pronged attack that mixes legitimate criticism with baseless charges and, in some cases, outright conspiracy theories.

It is similar to the tactics Mr Trump used against Mrs Clinton four years ago with unexpectedly devastating success.

Trump campaign spokesman Tim Murtaugh said Mr Biden will be portrayed as too liberal for most Americans, weighed down by questions about his son’s overseas business dealings and about questionable mental acuity at his age.

Brad Parscale, Mr Trump’s campaign manager, predicted Mr Trump would “destroy” Mr Biden, whom the president and his allies have nicknamed “Sleepy Joe”.

“President Trump is still disrupting Washington, D.C., while Biden represents the old, tired way and is continuing to coddle the communist regime in China,” Mr Parscale said.

Mr Trump’s team also believes he can win over disaffected Mr Sanders supporters who see Mr Biden as a consummate insider.

Shortly after Mr Sanders’ announcement, the president charged without evidence that Democratic leaders were plotting against Mr Sanders.

The Republican National Committee has already assembled an extensive research book and devoted 10 researchers ton Mr Biden who served as vice president to Barack Obama.

Before Mr Biden can shift his entire focus to Trump, the former vice president is tasked with winning over Mr Sanders’ sceptical far-left supporters, who have trashed Mr Biden’s record on trade, criminal justice, corporate America and foreign policy.

The party’s most progressive wing also fears that Mr Biden’s policies on health care and the environment, among others, do not go far enough.

For example, Mr Biden supports universal health care, but unlike Mr Sanders, he would preserve the private insurance system and offer Americans a government-backed “public option” instead of Mr Sanders’ signature Medicare For All.

Mr Biden’s advisers note that he had already begun reaching out to Mr Sanders’ aligned progressive organisations, including those focused on young people like the Sunrise Movement and the March For Our Lives.

Sanders suggested that any full-throated endorsement of Biden would come with strings attached. “We are talking to Joe and we are talking to his team about how we can work together,” he told CBS “Late Show” host Stephen Colbert.

In a sign of what he hopes will come from those talks, Mr Sanders said: “I hope to be able to work with Joe to move him in a more progressive direction.”

Mr Obama has not yet spoken on his former deputy’s effective coronation as presumptive nominee but he and former first lady Michelle Obama are ultimately expected to help rally the party behind Biden, who served for eight years as Mr Obama’s vice president.

Mr Trump tried to raise suspicion about why Mr Obama had yet to endorse Mr Biden, saying: “When is it going to happen? Why isn’t he? He knows something that you don’t know.”

Former presidents typically do not interject themselves in the primary process, and Mr Obama had long maintained he would not get involved until a nominee had been selected.

Mr Biden’s new status as the presumptive nominee affords him the freedom to move forward more openly with selecting his own running mate.

He has already started vetting potential vice presidents.

Mr Trump received three million votes fewer than Mrs Clinton 2016 but won a comfortable victory in the Electoral College after campaigning strongly in key states, winning over many working class voters who had previously been Democrats.