In a perfectly gerrymandered system, the party in power can win using only 25.1% of the vote - and that's if all districts have equal population. You can get by with even less if the districts have imbalanced populations. In that "perfect" system, you draw the districts so that your detractors are 100% of the population in the districts you know that you're going to lose, and your supporters are 50.1% of the population in the ares you want to win.
In real life, of course, it's messier and you can't draw the lines quite so perfectly, but here's a link to the districts near Chicago - look how oddly-shaped they are, especially as you get closer to the city center. (They'll probably change again next election season, doubly so if the other party gets control.) http://www.govtrack.us/congress/members/IL
In a perfectly gerrymandered system, the party in power can win using only 25.1% of the vote - and that's if all districts have equal population. You can get by with even less if the districts have imbalanced populations. In that "perfect" system, you draw the districts so that your detractors are 100% of the population in the districts you know that you're going to lose, and your supporters are 50.1% of the population in the ares you want to win.
In real life, of course, it's messier and you can't draw the lines quite so perfectly, but here's a link to the districts near Chicago - look how oddly-shaped they are, especially as you get closer to the city center. (They'll probably change again next election season, doubly so if the other party gets control.) http://www.govtrack.us/congress/members/IL