Joe Biden's call for unity is being undermined by the rush to erase Donald Trump from history

So much for the grand promise of unity. Joe Biden's rush to erase Donald Trump from history delivered a forceful poke in the eye - some would say worse - to the 74 million people who voted for the other guy.

Ironically, while the US Capitol riots were a disaster for Mr Trump and his legacy, they have also undermined Mr Biden's chances of bringing the country together in a post-Trump world.

Cheered on by an increasingly noisy left wing of the Democrat party, demanding that all things Trump be cancelled, the new president spent his first hours in office doing just that.

He is using everything available to him under his executive powers - what he can do without the approval of Congress - to wipe clean the last four years.

But in doing so there has been no attempt to offer an olive branch to Republican voters, or their representatives in Congress.

Senior Republicans have been taken aback by the extent of Mr Biden's opening measures, especially on immigration and climate change.

Some took it as confirmation of their fears that the new president, a moderate Democrat, would end up a passenger in a party careering left.

Mr Biden promised Mr Trump's voters he would work for them too. But so for there is little sign of it. And Republicans in Congress are nervous.

Mr Trump may have thought he had made some permanent changes that many Republicans supported, such as overhauling the US immigration system, and ending America's involvement in various multilateral agreements.

But on entering the Oval Office for the first time as president Mr Biden began a policy bonfire.

With the stroke of a pen he ended funding for Mr Trump's wall on the Mexico border. Seconds later, another swish of his pen sent the US back into the Paris climate accord.

Swish went the pen again. That was the US back in the World Health Organisation. And so it went on.

Mr Biden signed over a dozen such orders on his first night in the White House. There will be many more to come over the next week or so.

It was a faster start to eviscerating a predecessor's legacy than any other president in living memory.

And it was symbolic, showing his absolute determination to roll back vast swathes of what Mr Trump did.

At no time did Mr Biden acknowledge that roughly half the country had voted for the policies he was striking out.

He particularly zeroed in on immigration, an issue which propelled Mr Trump to the White House four years ago.

Mr Biden signed half a dozen orders contributing to a relaxation of the US immigration system.

Ultimately, many major immigration changes he wants to make will need legislation backed by Congress.

But his opening salvo has made finding Republican support improbable.

On his first day the bill Mr Biden chose to send to Congress was one that proposes an eight-year pathway to citizenship for many of America's estimated 11 million illegal immigrants.

He might as well have kicked Republicans in the shins. The bill will not pass and was instead a statement of intent to his own party.

Marco Rubio, the Republican senator, said it was a "non-starter". He added: "It's a blanket amnesty for people who are here unlawfully".

Mr Biden's executive orders on climate change also alarmed Republicans as a sign of what is to come, and made their cooperation less likely.

One established a temporary moratorium on new oil and gas leasing in the Arctic National Wildlife Refuge, which had been opened up by Mr Trump.

Another revoked a presidential permit, issued under Mr Trump, for the Keystone oil and gas pipeline.

Mr Biden will have some explaining to do on the pipeline when he speaks to a "disappointed" Canadian prime minister Justin Trudeau on Friday.

Thousands of workers face being laid off from the $8 billion project involving the US and Canada.

Mr Biden's actions are already having a real-world impact. Thousands of Hondurans joined a caravan in recent days hoping to reach what they believe will be a newly welcoming United States.

Meanwhile, left-wing rioters smashed windows at the Democratic Party headquarters in Oregon while carrying anti-Biden signs and demanding he back the Green New Deal.

Back in Washington senior Republicans, newly concerned about Mr Biden's political direction, have an unexpected ace up their sleeve - thanks to Mr Trump.

On the near horizon there looms Mr Trump's Senate impeachment trial. While Senate time is taken up with that, Mr Biden will find it difficult both to get his cabinet nominees approved, and to have legislation passed.

Although some Republicans in Congress want the impeachment process over quickly, others are beginning to see a lengthy trial of their own former president, Mr Trump, as an opportunity to slow Mr Biden down.