There’s no question: It’s a lot easier to reverse four years of policy than it is to reverse eight years of policy, as the Trump administration has shown. Trump has managed to roll back some of Barack Obama’s policies, especially those instituted through executive action during his second term. But the Affordable Care Act has proved very difficult to dislodge, despite a months-long frontal assault that consumed much of Trump’s first year in office.

But Biden isn’t really talking about policy, is he? He’s talking about the sense of despair and frustration that seems to suffuse much of the country today—a spirit that animated some Trump voters to support him in 2016, and has animated many of those who voted against him ever since. It’s different from policy, though it is inextricably related: You don’t get family separations at the border without the cruelty-driven worldview of the administration.

He’s also talking about the way Republican officeholders are behaving, which is another essential ingredient to Trump enacting his agenda. Biden has previously promised that GOP members will have an “epiphany” once Trump is out of office (and, presumably, Biden is in). “This ain’t your father’s Republican Party,” Biden said Monday. If your dad is Biden’s father’s age, or even Biden’s age, that’s true. If your father is younger, it probably isn’t. As political scientists have shown, both parties have become more ideologically homogeneous and polarized in recent decades, but the Republican Party has become especially polarized. (By some measures, the process started in the late 1970s, just as Biden was finishing his first term in the Senate.)

Read: Donald Trump and the politics of fear

Despite the inexorable process of polarization, Democrats continue to insist that Republicans will embrace bipartisanship any moment now. Seven years ago this month, Biden’s old boss told supporters at a rally that everything would work better after the 2012 election: “My expectation is that if we can break this fever, that we can invest in clean energy and energy efficiency because that’s not a partisan issue.” This didn’t happen. The idea that it would be more likely after a Biden victory over Trump is even more far-fetched, given that the process of polarization has continued another seven years, and given the passions that Trump arouses.

One needn’t accept the deep historical critiques of American society leveled by Elizabeth Warren and Bernie Sanders to acknowledge that Republican polarization isn’t a Trump-era phenomenon. Trump represents a culmination of the process, rather than a swerve away from it. The Republican Party will not always be the party of Trump, but it will never again be the party of Bob Dole. (Democrats back then denounced Dole as an extremist, too, of course. It’s never going to be the party of Howard Baker either.) Meanwhile, Trump has catalyzed the polarization of the Democratic Party as well.