So if Joe Biden won 306 electoral votes and more than six million more popular votes than Donald Trump—and he did—why did the Democrats go down in a heap in the Senate and House elections?

One way to begin to understand this split verdict is to look at the number of House districts that Biden carried. According to an estimate provided by The Atlantic’s invaluable Ron Brownstein, Biden got more votes than Trump in 223 congressional districts. Not coincidentally, the next House will likely have 222 Democratic members—giving them a measly majority of four.

That doesn’t mean there’s a one-to-one correspondence between the districts Biden carried and those that House Democrats won. It does mean, though, that American voters are ticket-splitting a lot less than they used to. When all the votes for all the contests are counted, probably fewer than 20 districts will have voted for one party’s candidate for president and the other party’s candidate for Congress. In both the Nixon landslide of 1972 and the Reagan landslide of 1984, the number of split-ticket districts was roughly 190.

Still, when the popular votes in House elections are done being tallied, I wouldn’t be surprised if, like Biden, the House Democrats come out with a six-million-vote margin over the Republicans. Big cities are home to a great many districts where Democratic House candidates carry 80 percent of the vote or thereabouts. Republicans increasingly carry rural districts by considerable margins, but with nothing like the numbers Democrats put up in major metropolises.

The Democrats’ problem is the distribution of voters. Given not only the gerrymandering of districts but also, more fundamentally, their contiguousness, Republicans have a structural advantage built into our governmental system—not just in the House, but in the Senate, the Electoral College, and state legislatures—so long as they are the dominant party in rural and exurban America and so long as the Senate and Electoral College disproportionately reward small states.

As I argued in my print piece in the forthcoming issue of the Prospect, the national identity of the parties has come to eclipse the more localized identities of House and Senate candidates (for which the disappearance of local news outlets is partly to blame). Democratic Senate challengers carried Arizona and Colorado, as did Biden, and lost North Carolina, Iowa, and Montana, as did Biden. Only Republican Susan Collins received enough split-ticket votes to buck this party-line trend (Trump lost Maine, but she prevailed). Even more remarkable is the electoral record of Democratic Sen. Sherrod Brown, a solid liberal who keeps winning elections in the otherwise increasingly Republican state of Ohio. There’s a lesson for Democrats in Brown’s relentless and principled commitment to the working class, in his mantra of "the dignity of work." That phrase was repeated multiple times by Biden, Kamala Harris, Janet Yellen, and Biden’s other economic nominees at their rollout event today in Wilmington. In an America where split-ticket voting is going the way of the dodo, the Democrats would do well—politically, economically, morally—to take their cues from Brown.