There are two ways to describe how the Democratic presidential primaries have gone for Sen. Bernie Sanders (I-Vt.).

In one narrative, Sanders picked up where he left off four years ago, coming into the 2020 contest retaining the core base of support he had built in that nomination fight. He rolled up three wins in Iowa, New Hampshire and Nevada — better than he did in 2016 — and seemed for a while to be in contention in South Carolina, a state he lost by 50 points then. After Super Tuesday, Sanders appears as though he might win California, the biggest state in contention, and to have done better in Texas, the second-biggest. Once all of the voting is done (weeks from now, thanks to California), he is likely to be at or near the top of the delegate count.

The other narrative is gloomier.

In that one, Sanders’s presidential campaign starts with a tie in Iowa and an easy New Hampshire win — just as happened in 2016. He won the Nevada caucuses in which he came short four years ago but lost South Carolina by a similar margin. On Super Tuesday, his primary competitor, former vice president Joe Biden, ran the table in the South, winning a straight line of states from Texas to Virginia. He also picked up states that seemed within Sanders’s grasp, including Minnesota and Massachusetts.

As of this writing, Biden leads the delegate race — a sentence that even on Monday seemed like an unlikely one to appear on Wednesday morning. That lead is likely to change as the California vote comes in, but what seemed a week ago like a springboard moment for Sanders now looks like the day on which he was dragged back into the fight.

2020 Democratic presidential candidates reacted as election results came in on Super Tuesday, when 1,357 delegates were up for grabs. (The Washington Post)

What's more apparent after Tuesday is that Sanders's path to victory has many of the same potholes it did in 2016.

That Biden performed as well as he did in the South suggests that the black vote, Sanders’s Achilles’ heel in his fight against Hillary Clinton, remains an obstacle to the Vermont senator’s success. In Virginia in 2016, Sanders won 16 percent of the black vote, according to exit polling. This year, preliminary exit polling has him at 17 percent. Biden didn’t do as well as Clinton, but Sanders didn’t do much better than he did four years ago. In South Carolina, a similar pattern: Sanders improved from 14 to 17 percent — meaning he didn’t really improve significantly at all.

In Texas, Sanders won a plurality of the Hispanic vote, running about 10 points better than he did in 2016, according to preliminary exit polls. He won an outright majority of young Hispanic voters. But he didn’t improve at all with black Texans and did significantly worse with white Democratic primary voters. He lost the state by 30 points in 2016 and is currently down to Biden there in single digits, but it is also a state in which he had a lead even coming into the day’s voting.

His strength in California is a bright spot, but it carries an asterisk of its own. Much of the vote in the state came from early and absentee votes that were cast before Biden’s post-South Carolina surge. Preliminary exit poll results suggest that Biden won a plurality of the vote from those who decided which candidate to support only in recent days (a pattern that held across Super Tuesday states). But Sanders likely banked enough votes to carry the day.

What’s instructive about comparisons with 2016 is how Clinton ended up winning. Because the Democratic Party allocates delegates roughly proportionally, running to a draw in a big state is less useful than winning a medium-sized state in a blowout. Clinton ran up big margins in heavily black Southern states that gave her a big delegate lead. Sanders won a slew of small states by big margins and ran even with Clinton in many larger states, but he never had big wins in big-enough places that would help him substantially eat into Clinton’s delegate lead.

In that sense, Sanders is better positioned now than he was four years ago. After Super Tuesday then, Clinton had a nearly 200-delegate lead over Sanders. This time around, Sanders and Biden will end up with a much closer, to-be-determined gap between them. The delegate fight could look more like 2008, when Clinton struggled to close a narrow deficit with Barack Obama, than 2016.

In the abstract, that seems like it would work to Sanders’s advantage. There are still some states with large black populations yet to vote, such as Georgia. But there are also a lot of smaller states of the sort where Sanders did well in 2016 and where he might be expected to perform better than Biden, if the last nominating contest is any guide.

Except that there’s another notable change that became apparent Tuesday: Biden is often doing better with white voters relative to Sanders than Clinton did in 2016.

In Vermont, Sanders’s home state, Biden will end up winning some delegates, something that Clinton wasn’t able to do. The surge in turnout in Virginia was a function in part of suburban white voters coming to the polls to support Biden. In 2016, about a quarter of the primary vote came from the D.C. suburbs. On Tuesday, preliminary exit polls suggest that nearly 4 in 10 votes came from that area — and Biden won an outright majority of the vote. In suburban areas across the state, Sanders performed 10 points worse than he did four years prior.

Sanders’s argument for his electability in November is predicated on the idea that he will spur a surge in turnout, particularly among young voters and the working class. Again looking at Virginia, whites without a college degree turned out more heavily in 2020 than in 2016, according to preliminary exit polls — and Biden beat Sanders by 15 points. About half the electorate was voters without a degree, up from 2016, and Biden beat Sanders by a 2-to-1 margin, a wider gap than Clinton enjoyed four years ago.

A Post analysis of the vote suggests that Biden won 60 percent of the vote from those who sat out the 2016 primary.

Super Tuesday clarified the Democratic nominating contest, but it did not end it. Sanders and Biden appear to be at the outset of a protracted, delegate-by-delegate fight. That’s a better position for Sanders than he found himself in four years ago. But his base of support has changed in ways that demand he find a different path forward in the remaining contests, even as it has become clear that any new path will present many of the old obstacles.