The Rust Belt has been central to Bernie Sanders’s case for the Presidency. Its factory towns were where he ground his arguments against the economic policies of the past half century. In the 2016 primaries, it was where he won surprising victories over Hillary Clinton, and, in the 2016 general election, it was where Clinton suffered shocking, narrow, and Electoral College–turning defeats against Donald Trump. In the election’s aftermath, it was where you could find both white voters who sprang for Trump and black voters who didn’t turn out (or were kept from turning out) for Clinton. Last April, Sanders took a four-day tour of the region, traversing Wisconsin, Indiana, Michigan, Ohio, and Pennsylvania. Everywhere, he attracted huge crowds, and everywhere, in addition to his message of economic reform, he offered an electoral argument. “Four years ago, despite losing the popular vote by three million votes, Donald Trump carried all of those states and won enough electoral votes to win the Presidency,” he said at a rally in Madison. “Together, we are going to make sure that that does not happen again.”

In the years since Trump’s election, Sanders’s supporters have advanced a Bernie-would-have-won argument that hinged on this corner of our national map. Sanders seized on this as he mounted his second Presidential run, bolstering the ideological argument he made in 2016 with an electability one. In addition to making the case for his progressive policies—Medicare for All, free public college, proper taxes levied on the wealthy—he and his supporters have insisted that his nomination made the best strategic bet for the Democratic Party. That argument had two parts. The first was that Sanders would mobilize new voters—young people, people alienated from politics, and voters of color—to form a large and formidable coalition. The second was that he would win back the Midwest. On March 3rd, when fourteen states voted on Super Tuesday, the first part of that argument was undercut: young voters didn’t turn out in notable numbers, black voters in the South went overwhelmingly for Joe Biden, and turnout surged in places that also went hard for Biden, like suburban Fairfax County, Virginia. A week later, with Sanders’s loss in Michigan, the second part of his electability argument fell apart as well.

In 2016, Michigan was perhaps Sanders’s biggest and most surprising victory. In 2020, it will go down as perhaps his decisive defeat. He seemed to telegraph the stakes this weekend, as he crisscrossed the state with prominent supporters, including Alexandria Ocasio-Cortez and Jesse Jackson. It wasn’t enough. The news networks called the state for Biden soon after the polls closed. Exit polls suggested that Biden had won black voters in the state by a two-to-one margin. In 2016, Sanders beat Clinton in Michigan among white voters without college degrees. Tonight, that demographic, too, went for Biden. In Luce County, in the state’s rural Upper Peninsula, a Sanders blowout in 2016 was almost exactly reversed.

Sanders accomplished a great deal this past year. He put together a multiracial coalition in a number of states, and he popularized calls for a fundamental reshaping of the government and the redistribution of wealth in America. A democratic socialist won the primary in California, the country’s largest state. He raised historic amounts of money from small donations, showing that a candidate who eschews rich donors can still compete in the post–Citizens United era. And, even as Biden racked up primary wins, the underlying numbers showed a stark generational divide: Sanders commands the support of young Democrats, while Biden has won thanks in large part to his support among older ones. But, after Michigan, those are starting to look less like strengths for Sanders to exploit than facts that Biden will have to address as he moves on to the general election.