Single-seat districts congressional districts are the cause of most, if not all, of the distortion of our elected bodies (relative to the ideological makeup of the population).
"But amidst the partisan fingerpointing and bickering, one core aspect of the way our government works gets a free pass. We hear a lot about campaign finance and gerrymandering, but single-member district elections –that is, having each House member represent one congressional district –are without doubt the single greatest cause of what is broken about Congress. They are the key reason why Republicans easily kept control of the House despite losing the popular vote to Democrats,and why the political center has lost out to partisans on both sides of the aisle. They turn four out of five voters effectively into spectators who have absolutely no chance of affecting their representation in Congress. They help keep women’s representation in the House stalled at less than 18 percent, and grossly distort fair representation by party and race."