Joe Biden has issued a rallying cry for the preservation of democracy and a dark warning that America could face political violence as it barrels toward next week’s midterm elections.

The US president used a prime time address on Wednesday to argue that his predecessor Donald Trump’s “big lie” about the 2020 election being stolen has become “an article of faith” in the extreme wing of the Republican party.

Biden delivered his address to supporters under a painted ceiling in an ornate room at Washington’s Union Station, which is within sight of the US Capitol that was stormed on January 6 last year by a furious mob of Trump supporters.

Behind him were eight US flags and a blue curtain – a less dramatic backdrop than the red and blue lights of his “Battle for the Soul of the Nation speech at Philadelphia’s Independence Hall two months ago, where he spoke on similar themes.

But just as that address was framed by Republicans as an attack on their voters, his latest remarks found little unity. The conservative Fox News channel ran captions such as “Biden ignores crime & inflation to talk about ‘threat to democracy’” and “Divider in chief”.

Its effect on an election in which 27 million people have already voted was also uncertain. A CBS News poll late last month found that 63% of likely Democratic voters say a functioning democracy is a bigger concern than a strong economy, but 70% of Republican voters say the opposite.

Biden acknowledged that there is much at stake in the midterm elections, just six days away, but insisted: “Make no mistake, democracy is on the ballot for all of us.”

He began his remarks, hosted by the Democratic National Committee, by citing last week’s attack on Paul Pelosi, the husband of House Speaker Nancy Pelosi, at their home in San Francisco. He noted that the hammer–wielding assailant had asked “Where’s Nancy? Where’s Nancy?” – the same words used by the rioters on January 6.

Trump’s false claims about a stolen election have “fueled the dangerous rise of political violence and voter intimidation over the past two years”, Biden said.

“We’re facing a defining moment. We must with one overwhelming, unified voice speak, as a country, and say there’s no place for voter intimidation or political violence in America.”

The midterms will determine control of Congress and mark the first nationwide test of American democracy since Trump lost the White House and his supporters laid siege to the Capitol. “I wish I could say the assault on our democracy had ended that day,” Biden remarked. “But I cannot.”

The president warned that it is estimated more than 300 election deniers are on the ballot across America this year with an impact he described as damaging, corrosive and destructive.

“As I stand here today, there are candidates running for every level of office in America, for governor, Congress, attorney general, secretary of state, who won’t commit to accepting the results of the elections that they’re running in.

“That is the path to chaos in America. It’s unprecedented. It’s unlawful. And it’s un-American. As I’ve said before, you can’t love your country only when you win.”

He called on voters to reject candidates who have denied the results of the vote which even Trump’s administration declared to be free of any widespread fraud or interference, urging them to “think long and hard about the moment we are in”.

“This is no ordinary year so I ask you to think long and hard about the moment we’re in. In a typical year, we are not often faced with the question of whether the vote we cast will preserve democracy or put it at risk. But this year we are.”

Biden sought to preempt potential disinformation and unrest on election night, pointing out that it takes time to count all legitimate ballots so voters need to be patient. In 2020 Trump falsely claimed that mail-in votes tabulated after election day were illegitimate.

He again identified Trump as the architect of the chaos. “He has abused his power and put the loyalty to himself above loyalty to the constitution. He’s made the big lie an article of faith in the Maga Republican party.”

Biden described “ultra-Maga” Republicans – a reference to Trump’s “Make America Great Again” slogan – as a minority but “driving force” of the Republican party.

Pointing to mounting concerns over political violence as well as threats of America’s long tradition of peaceful and accurate elections, he argued these Republicans are “trying to succeed where they failed in 2020 to suppress the rights of voters and subvert the electoral system itself”.

Biden added: “There’s an alarming rise in the number of people in this country condoning political violence or simply remaining silent. The silence is complicity.”

He described those who are willing to use violence to achieve political ends as a “distinct minority” in America, “but they are loud and they are determined”.

Many Americans remain pessimistic about the state of democracy. An October poll by the Associated Press-NORC Center for Public Affairs Research found that just 9% of adults think democracy is working “extremely” or “very well,” while 52% say it’s not working well.

Republicans condemned Wednesday’s speech. Senator Tom Cotton tweeted: “To Biden, “democracy” means one thing: Democrats having complete power.”

Ronna McDaniel, chairwoman of the Republican National Committee, said: “Desperate and dishonest. Joe Biden promised unity but has instead demonized and smeared Americans, while making life more expensive for all.

“While Republicans remain focused on the issues that matter most to voters, Biden and Democrats are flailing in the final days because they have lost touch with the concerns of families struggling to get by.”

Biden has made the global struggle between democracy and autocracy a defining theme of his presidency. In a heartfelt plea, he claimed that Americans can no longer take democracy for granted. “In our bones we know democracy is at risk, but we also know this: it’s in our power to preserve our democracy.”