President Joe Biden argued in a prime-time address that Donald Trump and his supporters' "extreme ideology" "threatens the fundamental core of our nation,

rallying Americans of all shades to combat what he portrayed as dark forces within the Republican Party attempting to undermine democracy.

Biden unleashed the trappings of the presidency in an unusually forceful and sweeping critique of Trump and what he said has become the dominant strain of the opposition party in his speech Thursday at Philadelphia's Independence Hall.

His rant came only two months before Americans go to the polls in highly contested midterm elections that Biden describes as a watershed moment for the country.

"Too much of what's occurring in our country today is not normal," he told an audience of hundreds, raising his voice over pro-Trump hecklers outside the building where the nation's founding was argued.

He claimed he wasn't blaming the 74 million people who voted for Trump in 2020, but added, 

"There's no question that the Republican Party today is dominated by Donald Trump and the MAGA Republicans,

" an acronym for Trump's "Make America Great Again" campaign slogan.

The intentional move by Biden to marginalise Trump and his supporters represents a sharp turnaround shift for the president, 

who preached his desire for national unity in his inaugural address.