Watch: Joe Biden Mixes up Granddaughter With Late Son Beau During Philadelphia Appearance

Joe Biden didn't slow down on the campaign trail on Tuesday, making a few key stops in Pennsylvania, including Philadelphia. During his visit in the City of Brotherly Love, Biden was caught on camera making quite the slip-up when talking about some of his family members.

"I want to introduce you to my grandchildren," Biden began to tell the crowd through a megaphone. "This is my son, Beau Biden, whom a lot of you helped to elect to Senate in Delaware." The former Delaware Attorney General was diagnosed with a brain tumor and passed away in 2015. Biden continued, "This is my granddaughter, Natalie." That's when he realized the error he made as he was overheard saying, "No wait, we got the wrong one." Natalie, as he clarified, is the daughter of Beau. The clip went viral across social media as many pointed to Biden's slip-up as a sign of weakness, claiming that his opponent, Donald Trump, has continued to push onto his supporters.

There were plenty of Biden supporters in the comments sticking up for the Democratic candidate. One response read, "Obviously he meant to say it was his son Beau Biden's daughter, and got mixed up. He visited Beau's grave this morning, and he's understandably the most nervous today that he's ever been." On the flip side, another user was turned off by Biden's apparent mental lapse, "Beau has been dead for five years. The man clearly has a cognitive issue and shouldn't be anywhere near politics yet alone the Oval office." Many others took this stance as another commented, "I was never voting for this guy but my gosh it hurts to watch how his mental decline is out there for everyone to see... very, very sad to watch at this point."

Trump has gone on the attack about Biden's cognitive capability. One example was a few days before the first debate in Pittsburgh at one of his rallies when he said Biden "doesn't have a clue." He continued to go down that route for much of his upcoming rallies. "He's a dumb guy," Trump claimed. "Always known as a dumb guy. But we look forward to seeing him in the debate."