Years back, a law professor told me that when she teaches a class on the drawing of legislative districts, she leaves the issue of multi-member districts for last because it solves all the problems too well and makes the rest of the material uninteresting.

I was reminded of that when I read Kim Soffen's Upshot column about the way geography rather than gerrymandering disadvantages Democrats in Florida when it comes to the US House of Representatives.

Even Democrats can't draw Congressional districts in Florida that don't favor the GOP. http://t.co/v1IlLHwoRJ pic.twitter.com/aclgyE5bAH — The Upshot (@UpshotNYT) July 14, 2015

Everything she writes is true. Given the concentration of the state's Democratic Party voters in high-density, deeply blue areas around Miami, it is extremely "natural" to draw a map that has a heavy GOP tilt.

But even though every state in the union does it this way, it's not a law of nature that you have to allocate Florida's 27 House seats by dividing the state into 27 equal population slices. You could easily treat the state as one 27-member district whose members are elected proportionately. That's how they do it in Germany, Denmark, the Netherlands, and many other countries that prefer not to be beset by highly politicized district boundary questions. A really big state like California or Texas you might want to split into two or three multi-member districts. And there are always some thorny issues to work out, like the choice of the D'Hondt Method or Sainte-Laguë method of tallying the votes.

The point, however, is that how to create a fair system, in which the number of seats in a legislature that a party receives is proportional to the number of votes it receives, is a solved problem.

The trouble for the United States is a deeply misguided 1967 law that banned multi-member districts. The government's concern was that a state like Georgia might say, "We'll just elect all 14 of our House members at large," and that way no African Americans would get elected. Of course this concern doesn't apply to a proportional system, which, if anything, would have the opposite result — you could ensure that black and Latino members would get elected without needing to resort to funny-looking majority-minority district boundaries. So the problem of holding fair elections in Florida isn't unsolvable, but it will take an act of Congress to fix — which is almost as bad.