I'd be hesitant to pick up a challenge offered on election stats by Dave Wasserman, and just as well I didn't waste my time on the Wisconsin offer. And he was offering $7,000, in personal payment, to anyone who could do it.
You have to know there's a reason no one could. And in that reason lies a significant reality of congressional politics circa 2018, a reason why Democrats have to work harder to accomplish as much as Republicans, and there's nothing shady about it.
Wasserman is an election stats analyst for Cook Political Report and Five Thirty Eight, two of the best analysis sites around, so the guy knows political numbers. (I watch his Twitter feed closely on election nights.) Yesterday, he pointed out that Wisconsin has a partisanship index - meaning the normal advantage of Republican versus Democratic candidates - of zero, which means in turn that in a statewide race, a candidate of either party starts out with theoretically even odds of winning.
That might logically lead to another conclusion: Since Wisconsin has eight U.S. House districts, each party might logically win four of the seats. The current delegation (which includes House Speaker Paul Ryan) has five Republicans and three Democrats, not drastically far off. But by choosing which voters to include, you can draw districts that advantage one party or the other.
Wasserman was able to draw a U.S. House map for Wisconsin that clearly favored Republicans in six out of the eight districts (a "GOP gerrymander" map). His challenge to his readers, with an award of $7,000, was to draw counterpart "Dem gerrymander" map, with a clear seven-point advantage for Democrats in six of eight districts. That would, in other words, do for the Democrats what he had just done for the Republicans.
He got a bunch of nerdy replies, with some close efforts. One replied (with a map attached), "Okay, so I don't think it's possible to create 6 districts that are exactly D+7, but I was able to create 6 districts that are at least D+6.5, which rounds up to 7, if that counts for anything."
But apparently, no one was able to develop six districts for Wisconsin that were as favorable for Democrats, as Wasserman was able to for Republicans.
Finally, Wasserman fessed up: "Answer: It's easy to draw the GOP gerrymander, but the inverse Dem gerrymander isn't just hard - it's mathematically *impossible.* Despite WI's even partisanship, there is such a thing as a partisan bias in spatial distribution."
Impossible? Yeah, it is, because so many Democrats are bunched together in tight urban areas (in that state, Milwaukee and Madison primarily) while Republicans are spread out, that creating a winning Democratic map becomes far harder. And not just in Wisconsin. The point is true all over the country.
In Oregon, for example, the addition of a sixth congressional district, which looks probable for 2020, may mean the Democratic infrastructure in the state accepting that the new district will be Republican. It may be too hard to design the districts so the state goes 5/1 Democratic, the way it's now 4/1.
This just relates to where you you live, or, where Republicans and Democrats live. It's not gerrymandering; it;'s just the result of normal mapmaking.