For 40 years, the poor white vote in America has largely belonged to the Republican party. For the first time in a very long time, that demographic is up for grabs, and the party that capitalizes on this chaos could be looking at electoral dominance for decades to come.

Last night, after Donald Trump won all five states in the northeast primaries, I watched in something like amazement as he railed against the loss of manufacturing jobs in America in his victory speech:

“I traveled through New York State,” he said, “and every place we went, manufacturing down 40 and 45 percent, and even more. Then we go to Pennsylvania and we see the same thing, you loo kat what’s happening with steel and so many other industries…and every single place I go is a disaster, manufacturing down 40, 45, 50, 60 percent sometimes…in a relatively short period of time. Our jobs are being sucked away from our country, and we’re not going to let it happen anymore, folks. We’re going to make it very, very difficult to do that, and when companies want to leave our great country, and lay off all these great people that in many cases helped build the country, there will be consequences for that company to pay.”

And later, after a reporter asked him about Hillary Clinton:

“I mean, Hillary’s…I call her ‘Crooked Hillary,’ she’s crooked. She’ll be a horrible president, she knows nothing about job creation, her husband signed NAFTA, which destroyed this country economically, I will tell you. You look at New York State, you look all over New England, you look at Pennsylvania, NAFTA was a disaster. Her husband signed it. It was a disaster for this country.”

Now, we could argue about how much Donald Trump actually cares about NAFTA, or whether he’s serious about repealing it or even imposing tariffs for American companies that outsource labor. (I get especially cynical when I remember that Trump’s own clothing line manufactures in China and Mexico.) But let’s skip that for now. Regardless of his true intentions, the fact that this rhetoric is coming out of the mouth of the Republican frontrunner is…well, it’s flabbergasting.

For the record, he’s right about free trade, which has been as bad for poor people around the world as it has been for working class Americans. But Republicans have always been huge advocates of free trade, for the simple reason that Republicans have always been the party of big business, and free trade means higher profits for corporations as they either outsource labor to low-wage nations, or use the threat of doing so to weaken unions and lower wages in America. Look, for example, at the positions on free trade agreements taken by John Kasich and Jeb Bush and Marco Rubio, the three most fiscally traditional Republicans in this year’s race. George H.W. Bush was president who first proposed the free trade agreement with NAFTA, and signed it in Dec. 1992, and no serious Republican contender since has opposed that deal or any of the others that followed.

But of course, the Republicans have not led this fight alone. Bill Clinton was the president who signed NAFTA into law, and without the support of many Democrats in the House and Senate, it never would have been ratified. President Obama has been instrumental in fast-tracking the Trans-Pacific Partnership, and Hillary Clinton was a strong advocate for that agreement before pressure from the progressive wing of the party led her to oppose it in this election cycle—an opposition that feels very insincere, and very temporary.

Meanwhile, more than a million jobs have been lost in America as a result of free trade agreements—700,000 alone due to NAFTA—and it has weakened labor unions and reduced wages at many of those that remain. You would expect a pro-labor candidate like Bernie Sanders to rail against free trade, and he does. What you wouldn’t expect, in a million years, is for the leading Republican to be speaking the same language.

So why is it happening? Any why aren’t his constituents revolting, even as the party leadership conspires to tank his candidacy at the convention?

To answer that question, we have to look at the strange coalition that has made the Republican party so successful since the the Reagan years. By demonizing liberals (and minorities), identifying several social “wedge” issues like abortion and gay marriage, and scaremongering on the very idea of higher taxes, the Republican elite has managed to secure the vast majority of the poor white vote in America for decades, even though GOP economics are positioned directly against the self-interest of those voters. (For a great look at this phenomenon, read What’s the Matter With Kansas by Thomas Frank). It has worked beautifully, but it was always doomed to be temporary—how long can you fool people into voting against themselves before they start to see the trick?

The answer, in America, is about 40 years. But as the economy gets worse and worse, and the effects of free trade are felt on a working class that has seen real wages decline and job opportunities vanish, poor white voters are starting to see the GOP establishment as the ruling class that it is. And it’s not like they’re going to turn to Democrats as an alternative—the neoliberal movement led by Bill Clinton relies on triangulation to win elections, and has abandoned the progressive base of the party and the working class in general.

With these voters abandoning ship on the left and right, what do the current coalitions of the major parties look like? The Republican establishment has been utterly bludgeoned on a national level, as evangelicals and working class whites flock away from traditional candidates like Jeb Bush. The centrist Democrats have managed to forge a very odd coalition of affluent whites and poor minorities to hold off the progressive wing of the party, but it’s very hard to imagine that alliance holding up past Hillary Clinton and her enormous name recognition—the interests of those two groups seem too disparate for the union to remain intact for long, as the generational divide in the party demonstrates. (The workaround here is for the Dems is to follow the Obama blueprint and run minority candidates with establishment interests.)

Which leaves the largest bloc in the United States unaccounted for: The poor white voters. Where do they turn?

In 2016, there is a race to secure the future of this demographic, but these voters feel betrayed by the establishment wing of both parties. They have flocked, in the primary elections, to two candidates: Bernie Sanders and Donald Trump. Both speak the same language on free trade and other economic issues, though Trump has also stoked nativist sentiment that holds particular appeal for those with “strong national identity.” He is an expert at making powerless people feel powerful, and at times this ends up looking very ugly. It also may give him an insurmountable advantage over candidates like Sanders who won’t exploit these tendencies and may always lack real support in parts of the country like the southeast, where racial tensions simmer at a higher level, and voters are not as open to the idea of a future Sanders-type coalition that includes blacks and Hispanics.

Which gives Trump an advantage—he’s speaking the economic language of the poor white voter without espousing liberal social views that those voters associate with the party of rich coastal elites. The Sanders advantage is that his economic positions cannot be called into question—he’s not a billionaire who has exploited NAFTA, and he has a long record of actually fighting for the economic principles he preaches. At a time when the poor white vote is in a state of flux, these are the two most likely beneficiaries of a unique electoral uncertainty.

To put it more simply, there is a silent contest operating beneath the surface of the 2016 election, and the question it asks is, “which party will poor white voters support for the next generation?” It won’t be the establishment wing of either party—those are big-money interests, and that message rings especially hollow as the economy gets worse—but if either Trump or Sanders can secure the nomination, they can remake the party in their image, and ensure that these poor white voters identify with that party for years to come. Which brings us back to reality: Trump holds the obvious advantage because he’s going to win his nomination, while Sanders is all but certain to lose.

With that in mind, maybe the Republicans should be a bit more welcoming of Trump’s candidacy. They have owned the poor white vote for 40 years, and at the moment when their hold on that demographic is looking incredibly vulnerable, they have a candidate who is showing them the way forward. So do the Democrats, for that matter. The question is, which party will take heed?