US President Joe Biden on Thursday warned that America's democracy was being threatened by what he called "extremists."

During a primetime speech at Independence Hall in Philadelphia, Biden took direct aim at former President Donald Trump and his "Make America Great Again" (MAGA) supporters, saying that "Donald Trump and the MAGA Republicans represent an extremism that threatens the very foundations of our republic." 

Biden said, America was "in a battle for the soul of the nation."

"Equality and democracy are under assault," Biden said. "We do ourselves no favor to pretend otherwise."

Trump's MAGA followers taking US 'backwards'

Biden cautioned that "MAGA forces are determined to take this country backwards. 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 called for Americans across the political divide, and specifically mainstream Republicans, to come out in defense of the country's democracy which he said could not be guaranteed.

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

Biden toughens stance ahead of midterm elections

With the midterm elections taking place in November, Biden's speech has formed part of growing Democrat broadsides aimed at Trump-aligned Republican politicians.

The focus on hard-line followers of the former president has marked an apparent shift in the strategy of the current administration, compared with Biden's first year in office when he had appeared loathe to even mention Trump by name.

On Thursday, Biden was careful in his wording so as not to lump all Republicans under the same banner. "There are far more Americans, from every background and belief, who reject the extreme MAGA ideology, than those who accept it," he said.

"Not every Republican, not even a majority of Republicans, are MAGA Republicans," he added. "But there's no question that the Republican Party today is dominated by Donald Trump and the MAGA Republicans."

In a statement, Iowa GOP chairman Jeff Kaufmann said Biden was using the tactics of an authoritarian regime and was "trying to turn his political opponents into an enemy of the state."

Last week, Biden likened "MAGA philosophy" to "semi-fascism," which did not sit well with Republican Senate Minority Leader Kevin McCarthy. He said Biden's comment "vilifies" millions of "hardworking, law-abiding citizens."

kb/sms (AP, Reuters)