So here are some of the questions his candidacy would help us answer:
How do Democratic voters feel about electing an old white guy? Fair or not, this is a real question for Biden. He’ll be 78 in January 2021, and while he seems energetic and mentally fit, there are legitimate questions to be asked about anyone’s ability to perform the extremely demanding job of president into their 80s (questions that also face Sen. Bernie Sanders, who’s a year older than Biden).
On the white question, Democrats have assembled the most diverse field in presidential campaign history, which reflects the fact that they are now the party of the new America while the GOP remains the party of older Christian white people. Many primary voters could decide that even if they like Biden, it’s time to give another kind of person a shot.
Is there really a moderate “lane,” and is that where you’d want to be? It has been reported that Biden believes that other candidates will split the liberal vote and he can win the nomination mostly with the support of the party’s moderates. Unfortunately for him, that ignores how presidential primaries work. Liberals might split the vote in a given contest, but a week later when you get to the next primary, some of those candidates will have dropped out or faded from consideration. After we get past Iowa and New Hampshire, Biden will probably be running against not 15 other candidates, but four or five. And then three. And then one. He’s going to need a majority.
At which point, we’ll find out if moderation really is what the Democratic electorate is after. When Biden refuses to endorse Medicare-for-all (or some version of universal coverage), how big of a problem will that be? Other candidates will have an emphatically progressive agenda, but it’s as of yet unclear what Biden actually wants to do as president. His impulse to find the middle of the road and say nice things about people like Vice President Pence whose views many Democrats find horrific may not serve him well.
How ready are voters to forgive the sins of a candidate’s past? This isn’t just a problem for Biden; questions have been raised about Kirsten Gillibrand’s shift leftward on issues as she went from representing a conservative congressional district to representing the state of New York in the Senate, and about Kamala Harris’s record as a prosecutor in San Francisco, and about Cory Booker’s embrace of charter schools as mayor of Newark.
But for Biden, there are some issues that the core of the Democratic Party’s base will be uneasy about: his performance running the 1991 Supreme Court confirmation hearings for Clarence Thomas; the way he defended his opposition to school busing in the 1970s; his work on the notorious 1994 crime bill; and his vigorous defense, as a senator from Delaware, of the credit card industry.
These issues are likely to come up in both interviews and town hall meetings, and it’s the latter we should watch. When Democratic voters stand before him and ask him to explain that record, is he going to have answers that will make the voters watching say, “Okay, he gets why all that was wrong, and now I trust him”?
Is this election about persuasion or mobilization? This is a question hanging over all contemporary elections. Do you win by persuading some of the other party’s voters to vote for you, or do you win by turning out your own voters? While you might like to do both, evidence is mounting that mobilization is far more important, because persuasion is so incredibly hard in a polarized age. Yet the rationale for Biden’s candidacy seems to be that he’s the guy who can appeal to those storied working class white voters.
Maybe that's true and maybe it isn't. But it's not clear that Democratic voters want to be told that the the only true path to victory is by putting aside their own more ambitious goals and kowtowing to people who voted for Donald Trump, which is a way of validating what Trump stood for in the first place.
Do gaffes matter? This may be less consequential than the other questions, but it’s going to come up. Biden is sometimes called a gaffe machine for his tendency to say cringe-worthy things in public. When he was vice president, it was easy to dismiss them as just Uncle Joe being Uncle Joe. (And for the record, despite his repeated claim that in Washington people call him “Middle-Class Joe,” nobody in Washington has ever referred to him by that moniker except himself.) While my general position is that gaffe-based media coverage is almost always a ludicrous distraction from the things that actually matter in a campaign, they could become an easy rationale for voters to turn away from Biden, particularly if he says things that are really offensive. Which there’s a good chance he will.
My own unscientific reading of Democrats tells me that while a lot of them like Biden, there aren’t that many who love Biden. But I could be wrong. Either way, his candidacy should bring a lot of clarity to the race.