The moment that progressive Democrats have dreaded for months finally arrived yesterday, as former Vice President Joe Biden announced his campaign for president via a video that leaned heavily on criticizing President Trump's "very fine people" response to the infamous 2017 neo-Nazi rally in Charlottesville, Virginia. "And in that moment," Biden intones, "I knew that the threat to this nation was unlike any I had ever seen in my lifetime."

One can wonder why Biden didn't have that moment earlier — perhaps when candidate Trump promised to ban all Muslims from entering the United States — while still recognizing that Biden might be underrated by most media observers. Certainly a lot of people who spend their days and nights parked on Twitter, where the activists stan hard for Bernie Sanders and the wonks go wild for Elizabeth Warren, seem to think that Biden's candidacy will evaporate once his half-full pot of water is put on the 24-7 burner of the actual primary.

Right now, though, Biden is at least arguably the favorite, having led almost every national poll going back to December 2016. And there simply isn't a ton of precedent for someone with Biden's consistent polling strength to just disappear in a puff of hot air absent some previously unknown scandal, like Gary Hart's 1988 extramarital affair revelations. At a time when the sitting president is a multiply-accused sexual harasser who has reportedly paid please-be-silent money to several past paramours, the bar for a Biden-destroying scandal is Olympic pole-vault high — so much so that accusations of inappropriate touching leveled at him by two women last month as well as long-simmering rumors that this behavior was commonplace for Biden have (depressingly) barely dented his numbers.

And while you might think anecdotally that presidential primary history is rife with frontrunners laid low by the time the delegates are awarded, the reality is very much the opposite. In 2016, for example, presumptive frontrunner Jeb Bush never polled more than 17 percent, as Donald Trump led the polls nearly every day from July 2015 onward. At this point in 2012, Mitt Romney led a crowded field of GOP hopefuls, and despite briefly falling behind Herman Cain and then Newt Gingrich, went on to win the nomination comfortably. While early polling has tended to be more predictive for Republicans than Democrats, it isn't meaningless either.

Early frontrunners have certainly coughed up leads. There was, of course, the 2008 Democratic primary, in which Hillary Clinton led eventual nominee Barack Obama by an average of 15 points from July to June 2007. Clinton, however, still nearly won the nomination and fought Obama to a tie in the popular vote totals. The last time someone who wasn't polling in the top tier at this point in the cycle won the Democratic nomination was 1992, when Arkansas Gov. Bill Clinton climbed past California Gov. Jerry Brown and a number of other more well-known candidates to win, a race that should remind us of how a lack of name recognition can hamper early numbers for candidates who later catch fire. But overall, 1992 might as well be Greek antiquity in terms of American political dynamics.

Biden has another piece of polling data to feel good about, and that is his consistent edge over the other candidates in head-to-head polling against Trump. In surveys going back to last March, Biden thumps him, often by double digits, with the average of the most recent polls almost an 8 point edge. That number is just +2.7 for Bernie Sanders, +1.7 for Kamala Harris, and a tie for Elizabeth Warren. At a time when the president's approval is mired in the low 40s, those numbers are not confidence-inspiring for Democrats desperate not to suffer through another four years of the nightmarish Trump presidency.

Democrats and Democratic-leaners have, not surprisingly, been telling pollsters that they prefer someone who can beat President Trump next year to someone who more closely aligns with their policy priorities. They also might remember, and regret, nominating Hillary Clinton in 2016 despite the consistent head-to-head polling advantage over Trump held by Bernie Sanders. These dynamics all spell trouble for the more ideologically progressive candidates, especially if these are the numbers we're seeing on Iowa Eve in January. Even people who really don't want Biden to be the nominee might be given pause by the chance of crushing the president by historic margins.

The former vice president also remains a popular figure, both nationally and especially with Democrats. Those who believe Biden is destined for a Hindenburg moment based on his two previous and unimpressive runs for the White House in 1988 and 2008 are missing one extremely important variable — even in '08 Biden was just a mid-tier senator from a tiny state, perhaps best known for his role in the Anita Hill hearings, mocked by the press as an undisciplined loose cannon, and reviled on the left for his Iraq War vote. He was the "Senator from MBNA," a tool of the financial elite.

He got less than 1 percent of the vote in Iowa in the 2008 caucuses and then promptly withdrew. If his career had ended that day we would not be having this conversation. But Biden subsequently spent eight years as Obama's right-hand man and still glows with the magic touch of the former president. He is now the veteran of two successful campaigns for the White House and boasts deep ties to the party's still important elites. And he's really not nearly the disaster in public that his now-dated reputation would suggest. He walked over both Sarah Palin and Paul Ryan in vice presidential debates and presumably knows not to plagiarize any more Neil Kinnock speeches.

All the sniping from the left about his (sometimes wretched but hardly Ted Cruz-like) policy record has also made everyone forget about Biden's incredibly appealing life story, one marked by unimaginable personal tragedy and also by great determination and achievement. You sell that narrative short at your own peril.

He also polls well with moderate Democrats. They might be outnumbered by liberals in the overall primary electorate but the latter could also be split between five or six different candidates. And while he didn't talk about policy in his announcement, Biden is likely to position himself in contrast to candidates pushing Medicare-for-all and free public college. Who is his competition for that moderate vote? Amy Klobuchar? Seth Moulton? Please. It's his for the taking.

Biden's problem, and it's a serious one, is that he is out of step with two overlapping groups of Democratic voters. Call it The Old Man and the Sea Change. The party's activists have moved far to Biden's left on issues of domestic and to a lesser extent, foreign policy. He has a long legislative trail in the Senate stretching back to the 1970s, that includes now deeply out-of-fashion votes for things like the Iraq War, the 1994 crime bill, and the tightening of bankruptcy regulations.

While the degree to which policy revulsion drove the revolt against Hillary Clinton in 2016 is wildly overstated, Bernie Sanders used a similar set of votes to often devastating effect to paint her as a warmongering, neoliberal tool of the carceral state, and this time around there will be multiple candidates taking aim at Biden's policy record. More so than any of the other candidates, Biden seems, perplexingly, to earnestly believe in a long-dead bipartisanship at a time when many on the left yearn to bulldoze the charred remains of the norm-based political order torched by two decades of Republican obstruction and procedural escalation and then roll around gleefully in the ash. Those activists, justifiably, are in the mood for vengeance, or as the recent Felice Brothers song about the election goes, "They want to eat their enemy's hearts and brains and lick the bloody plates."

Can Joe Biden mobilize voters who want both a more aggressive policy advocate and a brawler who thinks that fixing America's broken electoral system is more important than having pleasant lunches with Republicans? Will a campaign focused on Trump's outrages — which backfired on Hillary Clinton in 2016— really deliver independent voters to the Democrats? That all remains to be seen, but for now, observers chuckling about Joe Biden's inevitable flameout are kidding themselves.