The plan articulated by a group of Maryland Republicans is simple. Three counties from that state — Allegany, Garrett and Washington — become part of West Virginia. In essence, it takes the Maryland panhandle and makes it part of the state it sits atop. Not complicated.

There are a lot of similar threats made often, with various people nodding at them and mulling them over. And then, because this is a very complicated thing that many people in each state would dislike, it doesn’t happen. This one almost certainly won’t either.

What’s interesting, though, is what would happen if it did.

West Virginia and Maryland are very different states, despite their geographic proximity. West Virginia is very heavily White and very heavily Republican. (Those things tend to overlap, of course.) Maryland is much more diverse and much more Democratic.

The immediate effect of the transfer would be that Maryland would lose about 250,000 people, 4 percent of its population. West Virginia would gain the same number. And since the counties that would be switching are disproportionately White for Maryland, most of the population that transferred between states would be, too.

The change would look like this. Figures that decline, all on the Maryland side, are indicated with dashed lines.

As you might expect, by losing so many White residents (nearly 7 percent of the state’s total!), Maryland would become more densely non-White and more Democratic. (It would lose 73,000 people who cast votes for Donald Trump last year, compared with only about 40,000 who voted for President Biden.)

But here’s the thing. Because West Virginia is so White and so Republican, adding a less-densely White and less-heavily Republican group of counties would make West Virginia less White and more Democratic, too.

This doesn’t make intuitive sense until you think about the percentages. West Virginia is currently 89 percent White. Adding a group of counties that are only 80 percent White is going to bring that percentage down. Same deal with politics. Since West Virginia backed Trump by about 39 points last year, adding counties that backed him by only 30 points shifts the state to the left. Since West Virginia would be increasing its population by 14 percent, these effects aren’t small.

If you have a deep-red paint and add some pink, the mixture is not going to become darker red.

Again, this isn’t going to happen anyway, making this more of a thought experiment. But knowing how the demography and politics of both states might shift, those Republican officials advocating for it might soon find support from their colleagues on the left.