Biden, who served as a senator for over thirty years before becoming Barack Obama's VP, already ran for president in 1988 and 2008, but withdrew early on both occasions, ducking out of the 1988 race over a long-forgotten speech plagiarism scandal.
Creepy Joe
The latter meme, dubbed 'Creepy Joe' online, is based on a series of photos and video of the former vice president appearing to violate the personal space of multiple women and young children, and has given rise to a never-ending series of photoshopped images, many of them remembered after Biden formally announced his bid for the White House on Thursday.
Throughout the affair, Biden has maintained his innocence, saying he was "not sorry" for "anything" he had ever done, and justifying his behaviour by saying that "the times have changed" and that personal space norms were different when he was growing up.
Bromance With Obama
Another well-known source of Biden memes comes from the former vice president's close personal friendship with Barack Obama, with users tweeting an endless series of photos accompanied by hilarious captions to express the men's closeness over the years. With Biden's announcement that he was in the race, some users excitedly noted that they could hardly wait for the memes' return.
Gaffe Machine
The vice president's habit of saying the wrong thing at the wrong time, from swearing on hot mics, to making awkward (and perhaps) racist comments about minorities, has been widespread enough over the years for major networks to make 'best of compilations' about it, and to give rise to a special term: 'Bidenism'.
Following his announcement, users recalling this tendency to gaffe marked concerns over whether or not Biden would be able to defeat his greatest challenger – his tongue.
Biden-Trump Feud
Last but not least, there is the Biden-Trump feud, which appeared to seethe ever since Trump became president, but exploded in March 2018, after Biden said that if he and Trump were in high school and Trump bragged about 'grabbing women by the *****', he'd "take him behind the gym and beat the hell out of him."
The comment received an immediate response from Trump himself, who nicknamed Biden "Crazy Joe" and accused him of being "weak, both mentally and physically" while acting "like a tough guy." Biden later expressed regret over his remark, but not before the meme machine got ahold of it, with users debating whether a fight between the two would be good for America.
Donald Trump himself greeted his new challenger, welcoming "Sleepy Joe" to the race and saying he would see him in the general election if Biden made it past the primaries.