Cohn says we Americans have separated ourselves geographically by political preferences so that to get "fair" districts would in fact require radical gerrymandering. He concludes:
Could fairer districts moderate Republicans? Perhaps. (snip) But this isn't the rationale advanced by Obama, or others who blame the Hill's polarization on safe, gerrymandered districts, rather than fingering the real (and simpler) culprit: the wide ideological divide between conservatives and liberals.