Rank-and-file Democrats have had a fairly bad run politically since the 2008 elections. They lost the House of Representatives in 2010 and the Senate in 2014. They’ve lost more than 900 state legislative seats, 30 state legislative chambers, and eleven governorships. Republicans enjoy their largest majority in the House since 1930, and the largest percentage of state legislatures ever.

Open up your pundit suggestion box and you can pull out a panoply of rationales for this unprecedented misery: Backlash against an historically anomalous president.  Low turnout in midterm elections when left-leaning constituencies stay home in disproportionate numbers. Sophisticated GOP voter-suppression techniques supporting that low-turnout strategy. The post-Citizens United power of Big Money.

Democrats fear these combined factors translate to a protracted period of political doom. But what if it all can be explained with simply one fact: America suffered a financial crisis?

That’s one conclusion to infer from a new study by three German researchers on the political aftermath of global financial crises. Manuel Funke, Moritz Schularick, and Christoph Trebesch looked at 20 advanced democracies and more than 800 elections dating back to the 1870s. They found that elections following a financial crisis almost always benefit the far right, resulting in increasing political polarization. In other words, the rise of the Tea Party right could be merely a normal response to a banking meltdown.

The common assumption has been that major crises lift all fringe parties, whether on the left or the right, as people become disillusioned with failed institutions. But in the five-year period after a financial crisis, far-right votes increase by one-third, according to the study, while far-left votes rise only slightly. The most severe financial crises, like the Great Depression or the 2008 crash, produce even greater boosts for the far right. This data was consistent throughout the 140 years of study, even after controlling for different voting systems. 

Many of the democracies studied in the report are parliamentary, which allows for more rapid increases for fringe parties than a first-past-the-post presidential system like we have in the United States. But the evidence in the study does align with the bottom dropping out of Democratic politics since Obama’s first election. Not only are Republicans winning, they’re moving further to the right, as predicted by the study.

Financial crises also shrink government majorities, whether right or left—as you might expect after a period of economic stress. This makes effective governance more difficult. We’ve certainly seen that in the U.S., with gridlock bringing public policy to a near-halt since the 2010 elections.

This new research rebuts the pervasive theory that there’s something uniquely conservative about the American electorate—a perception that leads centrist Democrats to demand that the party trim its sails and broaden its appeal. Global financial crises have as much to do with the recent Republican sweeps as anything. Maybe it’s because financial crises are associated with institutional failures of regulation and oversight; maybe it’s because they create deeper recessions that lead to more discontent with the status quo; maybe it’s because the inevitable responses—bailouts of financial institutionstrigger a backlash because of their perceived unfairness. But whatever the reason, the universal result is far-right success.

There is one key difference, though, between what the German data suggest and what’s happened recently in the United States: The political effects of a financial crisis are supposed to taper off after five years. We’re now seven years from the onset of the crisis. And yet, last year’s elections delivered a continuing blowout of the left. Why?

It could be that the tapering hasn’t fully set in. But the more likely answer is that the upheaval of the post-crisis years fed back into our political system. Because banks were protected from the worst losses, they were able to maintain their political power, and even expand it when Republicans took over Congress. The combination of that regained strength and the wholesale destruction of our campaign finance system after the Citizens United ruling helped turn the financial crisis into conservative electoral success. And that feedback loop has not stopped running.

After the crisis, homeowners and workers took the losses while banks got bailed out. That helped expand wealth inequality, which was already accelerating. We know that poor people vote in smaller numbers than the wealthy, and red-state Republicans have worked hard to keep it that way through voter-ID and other laws to deny access to the ballot, creating a structural political advantage. Studies also show that high-inequality countries like the U.S. have a more polarized and more right-leaning policy leadership to begin with.

When financial crises hit, the right gets a bump. But when they hit in the U.S., they interact with structural factors that accelerate and lengthen the effect of the conservative benefit. So how can Democrats break the cycle? The answer lies in reversing bank power.

This is what a lot of liberal commentators get wrong when they only focus on the policy aspects of breaking up the banks. You can argue whether Glass-Steagall repeal led to the financial crisis (I think it played a role), or whether we need something like it again to ensure stability and safety. You cannot ignore the political economy behind such a move. As Georgetown Law professor Adam Levitin points out, the political power of the banking sector is diminished if they are fragmented and downsized. “The route to campaign finance reform runs through Glass-Steagall,” Levitin says, and he may be right.

Whacking the big banks’ political power wouldn’t just help progressives win elections, but would also create political space to actually regulate in the public interest and protect consumers, without Congress constantly undermining such efforts. And because of what we know about the political aftermath of financial crises, stopping them is more than an economic imperative. We should want to avoid the instability and gridlock that always seems to follow, mainly because they incapacitate efforts at recovery. We should want to reduce the record levels of political and economic alienation that accompanies a powerful financial sector as well.

This year, Democratic presidential candidates have split on whether to break up the banks or make technocratic fixes. But rhetorical flourishes won’t matter much if Republicans control Congress. Maybe the crisis-induced conservative lean will finally fade away by next November. But if—well, when—another crisis hits, the same cycle is likely to repeat itself. 

The right-wing surge after the financial crisis was predictable. So was its endurance when it interacted with the realities of American politics. But Democrats had a moment after 2008 to restructure the financial system, not just rebuild it. Failure to do so wasn’t just bad policy; it hurt at the voting booth.