Biden struggles to land lines as Trump lies in first presidential debate

Donald Trump and Joe Biden sparred over abortion and tax policy in the first presidential debate in which the president struggled to land his lines and the former president repeatedly made false claims about January 6, the national debt, and that he presided over the “greatest economy in the history of our country”.

Biden described Trump as “the worst president in American history”, citing a consensus of historians. Trump responded by extolling the historic virtues of his tax cuts. “Nobody has ever cut taxes like us. We cut taxes four times,” Trump said.

Trump regularly answered straightforward questions – about the economy, or abortion, or the opioid crisis – with non sequiturs about immigration or China. He also repeatedly spewed false claims about abortion, the environment, and the border. CNN moderators failed to factcheck Trump.

Biden’s voice at times sounded raspy – the campaign said he has a cold – and he frequently struggled to complete his thoughts. During one notable moment early in the debate, Biden was laying into Trump over his tax policies and stumbled as he was running out of time to speak, before blurting out: “We finally beat Medicare.”

After the debate, commentators focused on Democrats’ panic about Biden’s performance, with several suggesting the party needs to consider nominating a different candidate at the convention in August. “The biggest thing in this election is voters’ concerns – and it’s both swing voters and base voters – with his age, and those were compounded tonight,” Democratic strategist David Plouffe said on MSNBC.

Early in the debate, CNN moderator Dana Bash asked Trump about his position on abortion in a post-Roe v Wade environment.

“What I did was, I put three supreme court justices on the court and they killed Roe,” Trump said. “Right now, the states control it, and that’s the will of the people,” he added, noting that he favors exceptions to a ban. Biden defended Roe and legal abortion, and Trump responded by drawing the debate into a discussion of illegal immigration.

Related: Biden’s poor performance and Trump’s lies: four key takeaways from debate

Trump’s comments about abortion rested on a lie popular with religious conservatives: that Democrats favor policy that allows for abortion up until birth. He also falsely claimed that ending Roe v Wade protections was something “everyone wanted”, despite consistent polling that shows the public desires at least some access to abortion under the law.

And yet, Trump called Biden a liar presenting disinformation.

Trump argued that “millions of people” are coming across the border and receiving social security benefits – a claim without evidence. Trump also argued that the opioid problem could be traced to fentanyl manufacturing in China, smuggled into the US across the southern border.

Biden noted that he has a proposal to increase technology and staffing at the border that was rejected by Republicans in Congress at Trump’s behest.

The two candidates sharply differed in their memory and view of the war in Ukraine. Biden labeled Vladimir Putin a war criminal who would extend the war in Ukraine to neighboring Nato states like Poland. Trump, however, called Ukrainian president Volodymyr Zelenskiy the “world’s greatest salesman”.

Trump denied responsibility for the January 6 insurrection, instead arguing that then House speaker Nancy Pelosi bears responsibility for turning down national guard troops – one of several questionable claims.

Related: Factchecked: Trump and Biden’s presidential debate claims

Biden met that claim with exasperation on his face, a constant in the debate. Trump turned a question about his search for “revenge” into a diatribe about the president’s son, Hunter Biden.

The debate in Atlanta holds special significance to Black voters, both in the city where they are an important voting bloc in a swing state, and elsewhere. Biden said he doesn’t blame Black Americans for being disappointed in the progress that has been made under his administration, but noted the historic gains made in employment, loan forgiveness and other measures that have come during the last four years.

Trump’s response was to remind voters that Biden described Black criminals as “superpredators” early in his political career.

Asked about social security, Biden argued that a tax on millionaires would keep the system solvent without hurting anyone making less than $400,000 a year.

“The idea that we don’t need to protect seniors is ridiculous,” Biden said, touting the benefits of the Affordable Care Act.

Biden replied by describing Trump’s affair with adult film actor Stormy Daniels while his wife Melania was pregnant, calling Trump a man with “the morals of an alley cat”.

Trump denied sleeping with Daniels.