Gerrymandering and its consequences

Dan at YoungPhillyPolitics has a post on the possible consequences of past gerrymandering in PA (redrawing legislative districts to ensure stable seats for one party), which originally benefitted the Republicans mightily but could now make some of those seats vulnerable to Democratic opponents. Specifically, he muses that Bush's low approval rating and Kerry's relatively good showing in some Republican districts may be evidence that tides are shifting...