By Gary O'Donoghue and Sam Cabral in Atlanta and Washington, BBC
Donald Trump and Joe Biden have both held campaign rallies in the US state of Georgia, as their general election showdown comes into greater focus.
The former president, 77, slammed Thursday's State of the Union speech as an "angry, dark and hate-filled rant".
An hour down the road, President Biden, 81, unveiled new endorsements as he goes on the offence against his rival.
Both men are now within striking distance of clinching their respective party nominations for president.
Trump has so far amassed 1076 delegates and is 139 away from the number needed to lock in the Republican nod. Biden has collected 1859 delegates, 109 short of what he needs to secure the Democratic ticket.
Each man has the chance to complete the task in primary contests on Tuesday, including in Georgia.
Their shadow-boxing duel on Saturday also comes two days after Biden rebuked his predecessor's rhetoric and record in harsh terms during his State of the Union address to Congress.
Speaking in the northwestern city of Rome, Trump hammered his "grossly incompetent" opponent for "the most divisive, partisan and radical speech ever delivered by a president in that chamber".
"Joe Biden should not be shouting angrily at America," he argued.
"America should be shouting angrily at Joe Biden."
He also zeroed in on border security and the murder last month of Laken Riley, a Georgia college student allegedly killed by an undocumented immigrant.
Immigration is now the top concern for US voters, according to a Gallup poll released last month.
With supporters holding aloft photos of Riley, and her family and friends in attendance, the former president vowed to "demand justice for Laken" and "seal the border".
He also slammed Biden for rowing back on comments during the State of the Union in which he referred to the suspect as "an illegal". The president expressed regret in an MSNBC interview that he had not used Democrats' preferred term - undocumented.
Biden's controversial remark came during an exchange with top Trump ally Marjorie Taylor Greene, who rallied with Trump on Saturday in Rome, the city she lives in and represents in Congress.
Speaking about an hour's drive away in the capital city of Atlanta, Biden told supporters: "It can tell you a lot about a person, who he keeps company with."
He attacked Trump - who also hosted Hungary's Prime Minister Viktor Orban at his Florida home on Friday - for "sucking up to wannabe dictators and authoritarian thugs all over the world".
Reframing November's general election as "a contest between competing forces in a battle for the soul of this nation", the president reiterated his view that Trump's "story of resentment, revenge and retribution" was not in the best interests of voters.
Fresh off the buzz of a State of the Union watched on television by more than 32 million Americans, Biden's campaign for re-election is on the offensive.
He visited the battleground state of Pennsylvania on Friday, and will rally in Michigan and Wisconsin next week, while members of his administration are also fanning out across the country.
In coming weeks, "we will dramatically expand our volunteer engagement, scale up our battleground staff, launch our coalition groups, and invest in new paid media campaigns", campaign manager Julie Chavez Rodriguez said.
One such ad - that will target voters in seven swing states over the next six weeks - was launched on Saturday and directly addresses concerns about his age.
"Look, I'm not a young guy, that's no secret," it begins, before making the case that the veteran politician's experience has helped him "understand how to get things done for the American people".
During his Saturday appearance in Atlanta, Biden's crowd was small but enthusiastic, holding up signs passed around by organisers with the phrase "we're on board".
At the event, the campaign formally unveiled an endorsement from a trio of political action groups, who will spend $30m (NZ$48.5m) to mobilise black, Latino and Asian voters in support of the Democrat.
The president hit on many of the points from his punchy address on Capitol Hill, delivering remarks with energy that seems to have suffused his new style.
Keeping up that pace over the next eight months will be challenging, but it comes as no surprise his latest tit-for-tat with Trump came in Georgia.
Based on the results of their 2020 race, the southern state is the most marginal one in the country. Biden won here by fewer than 12,000 votes.
A big part of his victory came from almost nine out of 10 black voters supporting him, but recent polls have provided worrying signs, with a distinct lack of enthusiasm among many black voters for Biden's candidacy.
Polls show Trump in the lead here, but he too has problems. Georgia is home to one of the four criminal cases against him that could go to trial before the election, and he faces 13 felony charges over his alleged efforts to overturn his 2020 loss in the state.
In short, Georgia is on both these men's minds and victory in November may well hinge on its result.
This story was originally published by the BBC.