Supporters of Donald Trump see the president as the protector of an American they cherishSupporters of Donald Trump see the president as the protector of an American they cherish. Photograph: Spencer Platt/Getty Images

One version told of a president who is callous and cruel. “My dad was a healthy 65-year-old,” said Kristin Urquiza, whose father voted for Donald Trump in 2016 and died from Covid-19 in June. “His only pre-existing condition was trusting Donald Trump – and for that he paid with his life.”

The other spoke of a president blessed with compassion. Kayleigh McEnany recalled taking a phone call as she recovered from a preventative mastectomy. “It was President Trump, calling to check on me,” she said. “I was blown away. Here was the leader of the free world caring about me.”

The contrast was enough to induce a sense of whiplash.

But it happened over and over again during the past two weeks during the Democratic and Republican national conventions, held virtually for the first time due to the pandemic. The primetime television split screen displayed two radically different Americas – and two radically different diagnoses of its ills.

Democrats tore into Trump’s character and lack of fitness for office; Republicans paid tribute to his competence, common touch and generosity of spirit. Democrats hammered away at the pandemic, its death toll and the economic fallout; Republicans spoke of the virus rarely and preferred to sell optimism, promising a renaissance just around the corner. Democrats embraced the Black Lives Matter movement and quest for racial justice; Republicans stoked fear of “cancel culture” and suburbs overrun by violent mobs.

John Zogby, an author and pollster, observed: “We didn’t get a portrayal of disagreements; we got a portrayal of two completely different realities and that’s kind of astounding. If a Martian came down and watched both conventions, they would be puzzled and get back on the ship. It was amazing, a completely different reality about Covid, about the economy, about Black Lives Matter.”

When the smoke cleared from fireworks at the Washington monument that spelled out “Trump 2020” on the final night, the nation had a clearer idea of where the two armies have drawn battle lines before the November election.

Democrats set out to draw a contrast between their nominee Joe Biden’s empathy and experience versus Trump’s chronic inability to do a job he treats as a reality show. Michelle Obama, the former first lady, channeled the anguish of mothers across the country appalled by the 45th president’s crass conduct. “He is clearly in over his head,” she said. “He cannot meet this moment. He simply cannot be who we need him to be for us.”