(CNN) Joe Biden was under 40 when he was elected to the Senate, and he spent decades representing Delaware in the deliberative body, rising to lead the Senate Judiciary Committee and the Senate Foreign Relations Committee before serving eight years as vice president.

The man knows foreign affairs, and he knows politics.

He's accomplished all of this despite an extremely acute case of what has previously been diagnosed by media organizations as " foot-in-mouth disease ," something he'll have to manage during his latest run for President, which he enters as the prohibitive Democratic frontrunner.

He's a back-slapping kind of a politician who says things he probably shouldn't.

The first symptom that Biden has not shaken his long-running ailment came Wednesday, when he told an audience at an Iowa campaign stop that China is not a threat to the US, which will come as news to a lot of people in government and in both political parties who actually think China is the main threat to the US position in the world -- starting with President Donald Trump.

"China is going to eat our lunch?" Biden asked. "Come on, man."

"They can't even figure out how to deal with the fact that they have this great division between the China Sea and the mountains in the east, I mean in the west," Biden went on. "They can't figure out how they're going to deal with the corruption that exists within the system. I mean, you know, they're not bad folks, folks. But guess what, they're not, they're not competition for us."

In Iowa, soybean farmers are hurting because of the retaliatory tariffs the country has placed on US goods. Workers in the Rust Belt , which Biden wants to take back from China-obsessed Trump, are frustrated by outsourcing and the loss of US manufacturing jobs, many of them to China.

You could certainly argue that Russia is a larger military threat to the US. Or that terrorism is a more immediate threat to safety. But China's economic growth, its human rights abuses and its ownership of US debt all combine in a way to make it basically impossible to say China is no threat at all. His campaign immediately sought to clarify what he meant

But you can bet that this will happen again because it's happened so many times before.

The weird things Biden says can be harmless rhetorical flourishes, as when he hugged Barack Obama and told him, passing the Affordable Care Act was a "big f!@#ing deal."

Time Magazine , in 2010, compiled a list of the Top 10 times he was caught "saying the wrong thing at the wrong time."

CNN's Jake Tapper, as a White House reporter at ABC News, used to document Biden's slips in an occasional series called "Oh! That Joe!" for his Political Punch blog at the time.

Some examples:

You get the idea.

Pretty much every media organization operating during the Obama years has some kind of list of Biden's gaffes, if that's what they are, including CNN

Reading back over these old stories in the age of Trump, they seem quaint. Trump intentionally stokes racial divisions, he actively insults world leaders and political rivals, he says things that are untrue and spreads lies over and over again.

A key question for Biden and Democrats as he mounts his campaign to unseat Trump is whether the eye-rolling gaffes, on the order of asking a man in a wheelchair to stand up during a speech, or serious ones like underplaying the threat from China, make a blip in an America where the President has been documented lying 10,000 times by the Washington Post.

And there is some crossover between Biden's gaffes and Trump's insults. When in 2014 Biden called out the sad state of La Guardia airport in New York , saying it was like something from a "third-world country," it drew frustration from New York Democrats. Trump picked up the spirit of those comments with his own quips about La Guardia in 2015 and used it as part of his argument for more infrastructure spending.

Trump has been unable to deliver on that as yet, although he is currently in talks with Democrats on Capitol Hill. La Guardia, meanwhile, is in the midst of an $8 billion facelift and upgrade

Surely Trump will without irony point out each and every Bidenism on Twitter as it occurs even as his own staffers explain away the words that come out of his own mouth.

The more immediate problem for Biden is that he is the frontrunning Democrat in a primary with 20 other candidates. They will be hard pressed to ignore unscripted Biden moments. And so will a media that has been happy to point them out in the past. Whether any voters care any more is another question entirely.