Biden warns Trump loyalists taking America 'backwards'

US President Joe Biden took fierce aim Thursday at hardcore supporters of Donald Trump, warning they were determined to take America "backwards" by subverting basic freedoms, as he seeks to seize political momentum in a national address ahead of key midterm elections.

In excerpts of the prime-time speech Biden was to deliver in Philadelphia, the cradle of US democracy, the president called out the "MAGA" Republicans who embrace Trump's "Make America Great Again" ideology.

"MAGA forces are determined to take this country backwards," the 79-year-old leader charged. "Backwards to an America where there is no right to choose, no right to privacy, no right to contraception, no right to marry who you love."

Biden's speech took place near the building where the Declaration of Independence and the US Constitution were adopted more than two centuries ago.

With control of Congress for the remainder of his first term in the balance in November's elections, Biden did not mince his words in what was billed as an address on the "battle for the Soul of the Nation."

"Tonight I have come here to the place where it all began to speak plainly to the nation about the threats we face," Biden said, according to speech excerpts.

"For a long time, we've reassured ourselves that American democracy is guaranteed. But it is not. We have to defend it. Protect it. Stand up for it. Each and every one of us."

But the president also sought to strike an optimistic note, speaking of the "power we have in our own hands to meet those threats" and the "incredible future that lies in front of us if only we choose it."

 'Semi-fascism' 

The theme of Biden's speech harked back to an article he published in The Atlantic magazine in 2017, after a deadly white nationalist rally in Charlottesville, Virginia that he says spurred his presidential run.

"We are living through a battle for the soul of this nation," Biden wrote then.

After his election in 2020, the veteran politician initially planned to wage this battle through dialogue with moderate Republican lawmakers, and through economic and social policies aimed at the middle class.

But the talk of reconciliation has died down, as Biden faces a Republican Party still heavily influenced by Trump and polls seem to indicate the Democratic leader is better served by being more aggressive.

Last week, Biden accused Trump's supporters of being consumed by "semi-fascism."

The term sparked indignation in conservative ranks -- with the Republican Senate Minority Leader Kevin McCarthy charging that it "vilifies" "tens of millions of hardworking, law-abiding citizens.

A new poll published Thursday by The Wall Street Journal shows that if the midterm elections were held today, 47 per cent of eligible voters would cast ballots for Democrats, and 44 per cent would vote Republican.

In March, the Republicans had a five-point advantage.

The Democrats are hoping for an upset in November, in which all of the seats in the House of Representatives and a third of the Senate seats are on the ballot. Traditionally, the midterms don't favour the ruling party.

Things have been going well for Biden lately, however, with inflation slowing, a series of his landmark reforms finally pushed through Congress and Trump fighting off a series of criminal investigations. Polls show widespread support for abortion rights, which could put many Republicans on the back foot.

Trump is also planning an appearance in the state on Saturday to support his candidate in the Senate race, TV physician Mehmet Oz.