Donald Trump speaks during a elecction rally. File photo

Donald Trump, whose single turbulent term in the White House transformed the Republican Party, tested the resilience of democratic institutions in the US and threatened alliances abroad, will lead the GOP in a third consecutive presidential election after clinching the nomination on Tuesday.

With wins in Georgia, Mississippi and Washington state, Trump surpassed the 1,215-delegate threshold needed to become the presumptive Republican nominee. He'll formally accept the nomination at the Republican National Convention in July, by which point he could be in the remarkable position of being both a presidential candidate and convicted felon. Trump has been indicted in four separate criminal investigations and his first trial, which centers on payments made to a porn actress, is set to begin March 25 in New York City.

Trump's victory in the GOP primary ushers in what will almost certainly be an extraordinarily negative general election campaign that will tug at the nation's already searing political and cultural divides. He'll face President Joe Biden in the fall, pitting two deeply unpopular figures against each other in a rematch of the 2020 campaign that few voters say they want to experience again.

Joe Biden (left) and Donald Trump. File/AP

Trump, in a video to supporters Tuesday night, called it a "really great day of victory."

Looking forward to November, he said, "We now have to go on to victory because our country’s in serious trouble,” complaining about the border and the economy and claiming the US has "no respect on the world stage.”

The 77-year-old Trump is aided by Biden's perceived weaknesses. The 81-year-old president is broadly unpopular, with deep reservations among voters in both parties about his age and ability to assume the presidency for another four years, though he is not much older than Trump.

Rioters loyal to Donald Trump push against a line of police at the US Capitol in Washington on Jan. 6, 2021. File/AP

Biden is also struggling to replicate the coalition that ushered him into the presidency four years ago as some in his party, particularly younger voters and those on the left, have condemned his handling of Israel's war against Hamas.

While those dynamics may play in Trump's favor, he faces stiff headwinds in winning support beyond his base. A notable chunk of GOP primary voters backed his rivals, including Nikki Haley, who ended her campaign after the Super Tuesday races but has not endorsed Trump. Many of those voters have expressed ambivalence about backing him. He'll have to change that if he wants to win the states that will likely decide the election, such as Arizona, Nevada, Georgia, Pennsylvania, Michigan and Wisconsin - each of which he lost in 2020.

Associated Press