Fact check: The first 2024 US presidential debate

US President Joe Biden and Republican challenger Donald Trump traded barbs Thursday in the first debate of the 2024 election campaign.

AFP fact-checked what the candidates said on key issues.

- 'Migrant crime' -

Trump falsely claimed that under Biden, "we don't have borders anymore."

"Because of his ridiculous, insane and very stupid policies, people are coming in and they're killing our citizens at a level that we've never seen. We call it 'migrant crime.' I call it 'Biden migrant crime.'"

Following criticism over record border crossings and a bipartisan immigration bill that faltered in Congress, Biden signed an executive order early this month to temporarily shut down the border to asylum seekers after certain daily limits are hit.

That has amounted to "increased enforcement at the border," according to Nicole Hallett, director of the University of Chicago Law School's Immigrants' Rights Clinic.

Despite a few high-profile incidents, including the killing of a university student in the state of Georgia, there is "no evidence" of the migrant crime wave Trump described, Hallett told AFP.

"Crime is down across the country, even as migration has increased," she said.

Violent and property crimes are near the lowest levels in decades, according to FBI data from 2022, the most recent year for which figures are available.

"The overwhelming majority of violent crimes are committed by citizens," said Columbia Law School professor Jeffrey Fagan.

A June 2023 study found a decline in incarceration rates among immigrants from all regions since 1960.

Other research has also found migrants commit fewer violent crimes than US citizens -- including a Cato Institute report published this week that found migrants are less likely to be convicted of murder in the state of Texas.

Michelle Mittelstadt, director of communications at the Migration Policy Institute, said there is also no evidence to support Trump's claims during the debate that prisoners and people from mental institutions are flooding across the southern US border.

- Inflation blame -

Both Trump and Biden sought to defer blame for rising prices by criticizing each other's economic policies.

"He causes inflation. I gave him a country with essentially no inflation," Trump said after reciting his favorite -- but false -- line about ushering in the greatest economy in US history.

Biden countered by saying Trump "decimated the economy" and there were "no jobs" when he took office.

Both candidates misled by omitting the impact of Covid-19 on the economy.

When Trump left office, inflation was around 1.4 percent as the country continued to battle the virus.

Unemployment was about 6.4 percent, according to the Bureau of Labor Statistics, down from its peak of 14.8 percent in April 2020 after the outbreak.

Inflation started to climb in April 2021 as the country opened up. It continued to balloon under Biden's presidency, hitting a peak of around nine percent in June 2022 before falling to its current level of about three percent.

Several pandemic-related factors have contributed to that trend, including emergency spending packages under both Trump and Biden, a supply crunch and the war in Ukraine.

- Rewriting 6 January -

Trump attempted to deflect blame for the January 6, 2021 attack on the US Capitol, over which he was impeached, by pointing to former House speaker Nancy Pelosi.

"I offered her 10,000 soldiers, or National Guard, and she turned them down," he falsely claimed.

Pelosi's team has denied being made aware of any request for National Guard assistance until the Capitol was under siege by Trump supporters seeking to overturn the 2020 election.

In fact, Pelosi would not have even had the authority to reject the National Guard's activation had Trump authorized it.

The District of Columbia National Guard "reports only to the president," its website says.

Trump's claim traces back to remarks from former acting defense secretary Christopher Miller, who told a reporter that he recalled Trump floating the idea before January 6 of needing 10,000 troops.

But Miller later told lawmakers that "there was no order from the president."

The House committee that investigated the 6 January attack wrote in its final report that Trump "never gave any order to deploy the National Guard."

Trump also insisted again that "the fraud and everything else was ridiculous" in the 2020 election he lost to Biden -- claims officials from both parties have refuted.

Dozens of lawsuits aimed at overturning the election failed, while audits and recounts in battleground states reaffirmed Biden's win.