During Donald Trump’s presidency, I sometimes took comfort in the Yale political scientist Stephen Skowronek’s concept of “political time.”

In Skowronek’s formulation, presidential history moves in 40- to 60-year cycles, or “regimes.” Each is inaugurated by transformative, “reconstructive” leaders who define the boundaries of political possibility for their successors.

Franklin Delano Roosevelt was such a figure. For decades following his presidency, Republicans and Democrats alike accepted many of the basic assumptions of the New Deal. Ronald Reagan was another. After him, even Democrats like Bill Clinton and Barack Obama feared deficit spending, inflation and anything that smacked of “big government.”

I found Skowronek’s schema reassuring because of where Trump seemed to fit into it. Skowronek thought Trump was a “late regime affiliate” — a category that includes Jimmy Carter and Herbert Hoover. Such figures, he’s written, are outsiders from the party of a dominant but decrepit regime.

They use the “internal disarray and festering weakness of the establishment” to “seize the initiative.” Promising to save a faltering political order, they end up imploding and bringing the old regime down with them. No such leader, he wrote, has ever been re-elected.

During Trump’s reign, Skowronek’s ideas gained some popular currency, offering a way to make sense of a presidency that seemed anomalous and bizarre. “We are still in the middle of Trump’s rendition of the type,” he wrote in an updated edition of his book “Presidential Leadership in Political Time,” “but we have seen this movie before, and it has always ended the same way.”

Skowronek doesn’t present his theory as a skeleton key to history. It’s a way of understanding historical dynamics, not predicting the future. Still, if Trump represented the last gasps of Reaganism instead of the birth of something new, then after him, Skowronek suggests, a fresh regime could begin.

When Joe Biden became the Democratic nominee, it seemed that the coming of a new era had been delayed. Reconstructive leaders, in Skowronek’s formulation, repudiate the doctrines of an establishment that no longer has answers for the existential challenges the country faces. Biden, Skowronek told me, is “a guy who’s made his way up through establishment Democratic politics.” Nothing about him seemed trailblazing.

Yet as Biden’s administration begins, there are signs that a new politics is coalescing. When, in his inauguration speech, Biden touted “unity,” he framed it as a national rejection of the dark forces unleashed by his discredited predecessor, not stale Gang of Eight bipartisanship. He takes power at a time when what was once conventional wisdom about deficits, inflation and the proper size of government has fallen apart. That means Biden, who has been in national office since before Reagan’s presidency, has the potential to be our first truly post-Reagan president.

“Biden has a huge opportunity to finally get our nation past the Reagan narrative that has still lingered,” said Representative Ro Khanna, who was a national co-chair of Bernie Sanders’s presidential campaign. “And the opportunity is to show that government, by getting the shots in every person’s arm of the vaccines, and building infrastructure, and helping working families, is going to be a force for good.”

A number of the officials Biden has selected — like Rohit Chopra for the Consumer Financial Protection Bureau, Gary Gensler for the Securities and Exchange Commission and Bharat Ramamurti for the National Economic Council — would have fit easily into an Elizabeth Warren administration. Biden has signed executive orders increasing food stamp benefits, took steps to institute a $15-an-hour minimum wage for federal employees and contractors, and announced plans to replace the federal fleet with electric vehicles. His administration is working on a child tax credit that would send monthly payments to most American parents.

Skowronek told me he’s grown more hopeful about Biden just in the last few weeks: “The old Reagan formulas have lost their purchase, there is new urgency in the moment, and the president has an insurgent left at his back.”

This is the second Democratic administration in a row to inherit a country wrecked by its predecessor. But Biden’s plans to take on the coronavirus pandemic and the attendant economic disaster have been a departure from Obama’s approach to the 2008 financial crisis. The difference isn’t just in the scale of the emergencies, but in the politics guiding the administrations’ responses.

In “A Promised Land,” the first volume of his presidential memoir, Obama described a meeting just before he took office, when the economic data looked increasingly bleak. After an aide proposed a trillion-dollar rescue package, Rahm Emanuel, Obama’s chief of staff, began “to sputter like a cartoon character spitting out a bad meal.” Emanuel, according to Obama, said the figure would be a nonstarter with many Democrats, never mind Republicans. In Obama’s telling, Biden, then vice president, nodded his head in agreement.

Now Emanuel, hated by progressives, has been frozen out of Biden’s administration, and the new president has come out of the gate with a $1.9 trillion proposal. In addition to $1,400 checks to most Americans and an increase in federal unemployment aid to $400 a week, it includes a national $15-an-hour minimum wage, something dismissed as utopian when Bernie Sanders ran on it in 2016.

What has changed is not just the politics but the economic consensus. Recently I spoke to Jared Bernstein, a member of Biden’s Council of Economic Advisers, on “The Argument,” the Times podcast I co-host. When Biden was vice president, Bernstein was his chief economic adviser, and he said the meetings he’s in now are very different from those he was in during the last economic crisis.

Back then, Bernstein said, there was a widespread fear that too much government borrowing would crowd out private borrowing, raising interest rates. That thinking, he said, has changed. As Biden told reporters this month, “Every major economist thinks we should be investing in deficit spending in order to generate economic growth.”

It’s not just that the Democratic Party has moved left — the old Reaganite consensus in the Republican Party has collapsed. There’s nothing new about Republicans ignoring deficits — deficits almost never matter to Republicans when they’re in power. What is new is the forthright rejection of laissez-faire economics among populist nationalists like Senator Josh Hawley of Missouri, who joined with Sanders to demand higher stimulus payments to individuals in the last round of Covid relief.

That doesn’t mean we should be optimistic about people like Hawley, who wouldn’t even admit that Biden won the election, helping the new administration pass important legislation. But Republicans are going to have an increasingly difficult time making a coherent case against economic mercy for the beleaguered populace.

“This idea that the inflation hawks will come back — I just think they’re living in an era that has disappeared,” Elizabeth Warren told me.

However popular it is, Biden’s agenda will be possible only if Democrats find a way to legislate in the face of Republican nihilism. They’ll have to either convince moderates to finally jettison the filibuster, or pass economic legislation through reconciliation, a process that requires only a majority vote. Where Congress is stalemated, Biden will have to make aggressive use of executive orders and other types of administrative action. But he has at least the potential to be the grandfather of a more socially democratic America.

A moderate president, says Skowronek, can also be a transformative one. “It’s a mistake to think that moderation is a weakness in the politics of reconstruction,” he said, noting that both Abraham Lincoln and Roosevelt were “viciously” attacked from the left. “Moderation can stand as an asset if it’s firmly grounded in a repudiation of the manifest failure and bankruptcy of the old order. In that sense, moderation is not a compromise or a middle ground. It’s the establishment of a new common sense.”

There is, of course, no guarantee that Biden will fully rise to the moment. Skowronek has always expected that eventually American politics will change so much that the patterns he identified will no longer apply. “All I can say is that so many of the elements, the constellation of elements that you would associate with a pivot point, are in place,” he said. In this national nadir, we can only hope that history repeats itself.

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