Former Vice President Joe Biden committed another gaffe on the campaign trail, struggling to remember the word “escalator” during a campaign event on Sunday.

Biden, with his frequent lapses on the campaign trail, made the verbal misstep when addressing a crowd of voters in Miami, Florida to commemorate the start of Hispanic Heritage Month. The lapse occurred as Biden was attempting to attack President Donald Trump for having denounced criminals who enter the U.S. unlawfully during his initial campaign announcement in 2015.

“Remember when he came down, uh, down the uh — his golden escalator of Trump Tower,” Biden said, according to video of the incident by the Washington Examiner. “He announced on the way down, one of the reasons he was running was because of all those Mexican rapists.”

Biden’s struggle to remember the word “escalator” was the latest in a string of high profile lapses that have raised concerns about his fitness for the presidency. In particular, the 76-year-old former vice president has also shown an inability to recollect dates and places. Earlier this summer, Biden shocked the media establishment when he claimed to be vice president at the time of the mass shooting at Marjory Stoneman Douglas High School in Parkland, Florida.

“Those kids in Parkland came up to see me when I was vice president,” Biden said during a huddle with reporters in Iowa, before claiming that when the survivors visited Congress, lawmakers were “basically cowering, not wanting to see them. They did not want to face it on camera.”

The statement was quickly disproved, as the shooting, which resulted in 17 fatalities and over a dozen injuries, actually occurred on February 14, 2018 — more than a year after Biden left office.

Compounding problems for Biden is that his fellow 2020 Democrats have openly begun discussing his deteriorating capacities. Earlier this month, Rep. Tim Ryan (D-OH) inadvertently admitted to a reporter that Biden’s is “declining” in front of the public eye “almost daily.”