Shannon Stapleton / Reuters

Last night’s Democratic debate was a microcosm of the Democratic presidential primary: A hotly anticipated confrontation between Elizabeth Warren and Bernie Sanders mostly fizzled. Tom Steyer said some weird stuff. Pete Buttigieg struggled to speak about race. The commentariat was impressed with Amy Klobuchar, but voters shrugged. And at the end of the night, there was Joe Biden: underwhelming, maybe, but still standing at the head of the field.

The debate was the last prepackaged occasion for the contenders to make a big splash before Iowans caucus on February 3. Much can still happen—candidate-created moments, or external events of the Harold Macmillan variety—but time is running out, and three of the hopefuls will likely be absorbed by the impending Senate impeachment trial of the president they seek to replace. No one really seized the opportunity, giving Biden a sort of win by default. That follows Biden’s months-long pattern of failing to fail. Whether out of opposition to his politics or a desire for excitement, some Democrats and many pundits have expected Biden to collapse, but by the end of the debate, a resigned sense of Biden inevitability had settled on commentators.

One way to make sense of the situation is to think of Biden as the incumbent in the race. Even though the president is a Republican, the former vice president’s campaign is unfolding more as if Democrats are in power and trying to keep it than as if they’re challenging a sitting leader. Considering the race from this perspective helps explain Biden’s strengths and weaknesses.

Biden would certainly like to be seen as an incumbent. First, politically, he is reaching for the mantle of his old boss, Barack Obama, who remains broadly popular among Democrats and the general population. Second, ideologically, he has presented the Donald Trump presidency as an appalling anomaly (in contrast to candidates like Warren and Buttigieg, who frame it as a symptom of long-running maladies in American society). The Biden project imagines erasing the past four years and pretending as though Biden ran and won the 2016 election as Obama’s immediate successor.

Ersatz incumbency helps to explain some of Biden’s troubles, too. When incumbent candidates are challenged, their rivals lay out a similar set of complaints: The incumbent is too cautious in both his policies and tactics; he is too dependent on the coalition of the past, and will fail to turn out new and occasional voters; he is yesterday’s news, and the opposition will shred him for it. These are all critiques that have been thrown at Biden, and perhaps his critics are right about what will happen in a general election. If Biden is an incumbent, maybe he’s a little like Jimmy Carter in 1980, with the rest of the field, like Ted Kennedy, to his left, and Trump (in casting he would enjoy) in the role of Ronald Reagan.

But Carter was a true incumbent; maybe more useful analogies are to other quasi-incumbents. Consider Al Gore’s 2000 campaign. Gore was the sitting vice president, and despite his differences with Bill Clinton as the administration wore on, he was Clinton’s heir apparent. That was enough to clear the field of other Democrats—almost. Former Senator Bill Bradley of New Jersey ran against Gore, attacking him mostly from the left (even though Bradley’s Senate record was broadly similar to Gore’s).

Bradley’s run was serious enough that Gore tried to paint himself as an underdog in the race—an act of expectations-setting that the press didn’t really buy, nor did Bradley, who insisted that he was the real underdog. Gore won easily in Iowa, but Bradley came within a few points of tying Gore in New Hampshire. Then came Super Tuesday. Gore, buoyed by support among black voters, crushed Bradley. That effectively was the end of the race. Two days later, in the South Carolina caucus, Bradley pulled less than 2 percent—a major drop-off for a candidate who’d drawn 16 to 46 percent in every previous contest.

That’s the best-case scenario for Biden. The less rosy one is 2008. Hillary Clinton’s claim on quasi-incumbency was a little different and weaker; there had been eight years of a Republican president, though Clinton had been first lady in the last Democratic White House. Like Gore, Clinton was relying on black voters to help her hold off a challenge from Barack Obama, who—it is perplexing to remember now—was accused of being not black enough or unable to win. But by the South Carolina primary, Obama had proved his viability, and he won the state with the help of a large majority of African American voters. From there, it was a long and acrimonious march to an Obama nomination.

Historical parallels only go so far. The former vice president remains a weak front-runner. This is especially true in the first two states, Iowa and New Hampshire, where the race is tight. Losses there might hobble Biden going forward, but for now, he still seems likelier to win than any other candidate—maybe somewhere between Gore and Clinton.

But if the Democratic candidates continue to sleepwalk through the primary as they did through the debate, the relevant question will no longer be why Biden is so resilient: It’s because he’s effectively the incumbent. The better question is why his rivals have proved unable or unwilling to marshal the sorts of harsh attacks that Kennedy, Bradley, and Obama were able to against other quasi-incumbents.

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