Ron Brownstein has a really excellent article out today on how the Republican Party is now as firmly opposed to legal immigration as they are to illegal immigration. He’s done a deep historical dive into the roll calls of various immigration bills to demonstrate his point. The implications of Brownstein’s piece are quite troubling. To understand why, let me begin with where we presently stand:

In the House, about 85% of Republicans represent districts where the foreign-born share of the population was lower than the national average of 13.5% in 2016. Similarly, 42 of the 51 Republican senators represent the 30 states where immigrants compose the smallest share of the population, mostly in the South, the Midwest and the Mountain West. Republicans hold only nine of the 40 Senate seats in the 20 states where immigrants constitute the largest share of the population, most of them along the coasts. In 2016, Trump’s pattern of support followed those tracks too: He won 26 of the 30 states with the smallest share of immigrants, but lost 16 of the 20 with the highest.

We do not know how the midterm elections will turn out at this point, but it’s a safe bet that they will result in a more complete sorting of the electorate. The two most likely Democratic pickups in the Senate are in Arizona and Nevada, which are both well above the national average in their diversity. Democrats in North Dakota and Indiana are the most vulnerable, and both states are below average in their diversity. The Republican seats most likely to fall to the Democrats in the House are from highly diverse districts, many of them in growing suburban areas that have traditionally been rock-solid for the Grand Old Party. If any House Democrats lose their seats in November, they will most likely come from rural or exurban districts that are low on the diversity scale.

Within Democratic circles, there’s a debate about whether the Democrats can maintain their commitment to the poor and to urban issues if their center of gravity moves toward the affluent suburbs, and also about whether the party can or should do more to compete in rural areas. But a lot of this is beyond their control. The president’s policies and rhetoric, increasingly being backed by the Supreme Court, are creating a kind of tribal divide over race and region that no amount of Democratic messaging can overcome. Trump is moving suburban voters into the Democratic Party more efficiently than the Democrats could ever manage to do themselves, and he’s solidifying his rural support in the process. Political professionals can’t do much but watch this tsunami roll over the country in November and then analyze the carnage.

What we’ll probably see is a good night for the Democrats and a very concerning night for the country as a whole. What remains of the GOP will be more nativist, more provincial, more culturally and regionally isolated and homogeneous, and significantly less affluent and educated.

Democrats overestimate how rich the Republicans are to begin with, but after November they’ll be less of a country club party than they’ve ever been, and also more Southern, more evangelical and more advanced in age.

This is all going to make the Republican Party more dangerous and more of a threat to democracy. It’s also going to remove whatever moderation they currently have on the issue of immigration.

The Democratic Party will change, too, in some ways that many people will not like. That’s kind of inevitable anyway for any party that grows, even temporarily, beyond its recent historical size. But, as I’ve mentioned several times before, the Democrats will become the owners of a highly counterintuitive, unnatural and unstable alliance of cities and suburbs. This won’t resemble the old FDR coalition, with its odd admixture of the Solid South, the farmer-labor movement and the ethnic urban machines of the North. The Republican Party will be culturally shut out, like never before, from many of the most affluent and best educated places in the country. And if they follow Trump’s lead on trade, tariffs and immigration, they’ll start losing the small business community, too.

In general, it’s a good thing for the current Republican Party to lose power, but this is not going to teach them a lesson. It is going to do the very opposite.