The safe seats of the US House of Representatives

The distribution of different types of seats over the past six elections.
I’ve moaned about American politics before, but I don’t think I had any statistics to back me up last time.

However, Nate Silver has written an excellent article on Five Thirty Eight about the the development of ultra-safe, strongly partisan seats in the House of Representatives. He writes: “As these figures make clear, the number of swing districts has been on a steady decline since at least 1992, and the number of landslide districts on a steady rise.”

I think the obvious solution would be to take redistricting out of the hands of politicians, but for some bizarre reason this doesn’t always seem to appeal to Americans.