CNN is far from alone. It's common across the national media to see Biden pegged as the safest candidate for Democrats to put up to unseat Trump. He's got that secret sauce: electability.
"Sure, Democrats think he's electable, but they believe a half-dozen other candidates are, too," Leonard, the news director of two Iowa radio stations, told me. "No one I have spoken with sees Biden as more formidable than other top candidates."
But this thinking - much of it driven by early polling - creates a self-perpetuating effect: Biden is the front-runner, so he gets more media coverage.
"Joe Biden has done something no other Democrat has been able to do in this race: Command attention from all cable networks, and have them stream his entire event live," Washington Post political reporter Matt Viser tweeted last week during Biden's Iowa visit.
That coverage decision captures the electability delusion in action - and it cuts both ways.
Was Alexandria Ocasio-Cortez seen as electable?
Certainly not. Not until the Democrat rolled to victory last year in her New York City primary against entrenched incumbent Representative Joseph Crowley and soon afterward became the youngest woman ever elected to Congress.
Some news outlets didn't even have her photograph available on election night; and the New York Times, her hometown newspaper, hadn't written a full profile of her during the campaign.
Was Hillary Clinton seen as electable?
More than electable, she was inevitable - the crowned queen of 2016, from about 2013 on. Until, of course, she wasn't.
"So-called electability is no more a science than astrology. Indeed, it is often little more than calcified prejudice," Boston-based political activist Jonathan Cohn wrote recently.
On one level, seeing Biden this way is understandable. The former Vice-President is out front in poll after poll.
On another level, it's downright unfair to other candidates at this early stage - and it may be dangerous to the Democrats' quest to unseat Trump.
Salon's Amanda Marcotte finds it troubling to see Trump going after Biden with nicknames and other attacks, but not because she feels sorry for the former Vice-President.
No, her theory is that Trump - with his unerring instinct for steering the media caravan - is focusing on Biden because he knows the former veep may be relatively easier to beat.
"Biden's centrism, his big mouth, his age and out-of-touchness, and his handsiness sets him up to be beset with a 'both sides are the same, so don't vote' campaign targeting the same voters who sat out 2016," she tweeted.
When I followed up with her, Marcotte wrote: "I don't have a problem with calling him the front-runner at all, since that's just a fact, but I do think it's unfair to take his political argument for himself ('electability') as a fact instead of an opinion/argument."
The Washington Post has decided, for now, not to use the term "front-runner" for Biden in its news coverage, according to an all-newsroom memo in May from National Editor Steven Ginsberg, "given the continued volatility among the candidates at this early stage." Some other news organisations are showing similar restraint.
Wasn't former Florida Governor Jeb Bush looking pretty electable early in the 2016 Republican primary campaign? Conversely, before the 2008 election, weren't pundits busy doubting whether the United States was ready to elect a black president?
Wrong, and wrong again.
For months now, I've heard network news chiefs, and political editors and reporters of all stripes, insist - often as they sat on soul-searching journalism panels - that it would be different this time: less horse race, more listening to the American people's concerns.
To their credit, there does seem to be more effort to talk to voters in the field, all across the country, not just in the Acela corridor of New York City to Washington.
Certainly, campaign staffs are bigger than ever at many news organisations. But that often leads to more horse-race coverage, rather than a deeper understanding of communities.
The excitement about the latest polls puts all that reporting effort in the background - even though it's too early for polls to be very meaningful, at least when forecasting the general election.
Combine that with the unquenchable thirst for a narrative, a simple story for savvy journalists to tell news consumers, and before you know it, you've got the pseudoscience of electability. Cable news pundits, though not alone, are especially culpable.
The lust for narrative often comes with a hefty side order of unexamined sexism, as in: "Biden's more electable than Warren or Harris because Democrats already tried running a woman and failed."
We don't know that, and it may be dead wrong.
The truth is that journalists and pundits are bad at predictions. They should have learned that when Trump - a candidate so manifestly unsuited to be president that he couldn't possibly win - blew their minds by doing just that.
