President Biden has said Donald Trump is “willing to sacrifice our democracy” to regain power – as the US Supreme Court agreed to look at questions over his eligibility.
Mr Trump is favourite to be his rival again in November’s election.
President Biden attacked his ambitions and motivations, repeatedly referencing the 2021 storming of the Capitol by Trump supporters.
It came as the US Supreme Court agreed to hear Mr Trump‘s appeal over Colorado’s decision to disqualify him from its presidential primary elections.
The state of Maine has also followed suit.
The Supreme Court – which is weighted in his favour – could now make a decision that will settle such eligibility questions.
It indicated a speedy decision, scheduling oral arguments for 8 February, ahead of the Colorado primary on 5 March.
The states excluded him over language in the US Constitution’s 14th amendment that bars people who “engaged in insurrection or rebellion” from holding public office.
A statement by the Trump campaign said it looked forward to a ruling that would “affirm the civil rights of President Trump, and the voting rights of all Americans”.
Speaking in Pennsylvania on Friday, President Biden said the election would be a fight for the country’s soul and “all about whether democracy is still America’s sacred cause”.
“Democracy is on the ballot. Your freedom is on the ballot,” he said.
He painted Mr Trump’s re-election campaign as a backward-looking ego-trip and “all about him, not America”.
The Capitol riots, in Washington on 6 January 2021, saw Trump supporters run amok after he made false claims the election had been “stolen”.
Mr Biden called the event one of the “worst derelictions by a president in US history” because Mr Trump did not intervene.
“He told the crowd to fight like hell. And all hell was unleashed,” Mr Biden told supporters near Valley Forge, Pennsylvania.
“Then as usual he left the dirty work to others. He retreated to the White House.”
“We nearly lost America – lost it all,” Mr Biden added.
Five people died due to the chaos and dozens were injured, as thousands descended on Washington to try to stop the election result being certified.
Read more:
This year’s election will shape the rest of the world – analysis
What legal cases is Trump currently facing?
‘Extremely high’ chance of Trump being convicted in 2024
The ex-president is promising “revenge and retribution” if elected again and his campaign has glorified the riots, said Mr Biden.
He said Mr Trump’s description of his opponents as “vermin” was the “exact same language used in Nazi Germany.
Mr Biden also hit out at Mr Trump’s attempts to overturn the 2020 result, saying he had lost 60 court cases and “exhausted every legal avenue”.
The former president faces dozens of criminal charges related to his efforts to reverse his election loss.
However, he says top Democrats are themselves trying to subvert democracy by using the legal system to stop his campaign.
Ahead of Mr Biden’s speech, the Trump team put out an ad calling Mr Biden “the true destroyer of democracy” and referencing the special counsel’s investigation into his actions on 6 January.