Donald Trump and Hillary Clinton on Friday take their fight for the White House to battleground states seeking to capitalize on back-to-back party conventions that offered starkly different visions of America.
The Democrat and first woman nominee for a major party will tour Pennsylvania and Ohio by bus, while Trump jets to Colorado, where his plan to build a wall on the Mexican border could resonate with angry whites but repel Hispanics.
It opens a new chapter in what is already one of the most divisive presidential campaigns in modern US history after Republicans and Democrats spent the last fortnight formally selecting their nominees.
Just over 100 days before polls open on November 8, both parties are divided, both candidates are profoundly unpopular and the race is tight.
With Clinton looking for a post-convention bounce, the most recent poll average, collated before she accepted the nomination on Thursday, gives Trump a 0.9 percent lead according to RealClearPolitics.
The Republican candidate on Friday trashed her speech and launched a savage assault on key surrogates who endorsed Clinton: fellow New York billionaire Michael Bloomberg and a retired US general.
"I just beat 16 people and am beating her!" he tweeted in reference to the Republicans he defeated to clinch the nomination.
His campaign dismissed her convention speech in Philadelphia as "an insulting collection of cliches and recycled rhetoric," that was "delivered from a fantasy universe, not the reality we live in today."
Bloomberg, a former New York mayor and political independent, "never had the guts to run for president," while John Allen "failed badly in his fight against ISIS. His record = BAD," fired off Trump.
Both conventions featured withering personal barbs, with Republicans in Cleveland chanting "lock her up" against Clinton and Democrats painting Trump as a threat to US democracy.
Experts predict that "negative partisanship" -- voting against a candidate -- will play a major role in deciding who makes it to the White House.
On Friday, Clinton's running mate, Virginia Senator Tim Kaine, defended her more positive portrayal of America, in stark contrast to Trump's, and denied it was out of sync with an electorate that feels the country has lost its way.
"Even in a time when people have anxiety, I don't think what they want is leaders who stoke the pessimism," he told CNN.
Kaine said his first words to her on stage after her acceptance speech were: "It is a great country and you just made it a lot greater."
Kaine will accompany Clinton on the journey through so-called "rustbelt" states which are vital parts of almost any strategy to garner the 270 electoral college votes needed to win the presidency.
In an election year that has seen the voices of the hard right and the hard left become more dominant, Clinton is making a bold play to seize the political center-ground.
A string of high profile Republicans, including the party's last presidential nominee Mitt Romney, have publicly stated they cannot vote for Trump because of his populist policies. This means some Republicans can be won over.
Clinton vowed Thursday to be a president for all Americans "for the struggling, the striving and the successful. For those who vote for me and those who don't."
On the convention floor, delegates waved American flags and chanted "U-S-A" in scenes of extreme patriotism more usually seen at Republican rallies.
Clinton also made a pitch for disgruntled working class voters, who have formed the backbone of Trump's base, saying that her priority as president would be to create "more good jobs with rising wages."
At the Republican convention Trump doubled down on controversial plans to clamp down on crime and on immigration from countries -- including France -- that he deems "compromised" by terror attacks.
"The crime and violence that today afflicts our nation will soon, and I mean very soon, come to an end," he told delegates. "Safety will be restored."
Both Clinton and Trump donated large chunks of convention time to softening their public image.
Clinton's daughter Chelsea described a mother who liked to watch "Pride and Prejudice" while Trump's daughter Ivanka claimed her father would fight for equal pay for women and affordable childcare.
While Trump portrayed himself as a tough guy, Clinton used her own address to temper an image forged over decades of withering political trench warfare.
"It's true," she said. "I sweat the details," be it the amount of lead permissible in drinking water or the cost of prescription drugs.
"It's not just a detail if it's your kid, if it's your family," she said.