WPT, in a companion report, found that the strategists’ predictions in the more than 50 GOP-held Assembly seats facing Democratic challengers in 2012 were accurate, on average, to within a single percentage point. The GOP incumbents won all but three of these races.

One way to maximize partisan advantage is to pack as many opposite-party voters into as few districts as possible. In the district that acquired the shorn majority of Beloit, Democrat Janis Ringhand won with 64 percent of the vote, up from her 53 percent margin of victory in 2010.

In the upcoming Nov. 4 election, the Democrat seeking this seat is unopposed; so is Loudenbeck. Partisan redistricting took two competitive districts and made one so overwhelmingly Democratic and the other so safely Republican that general election voters will have no choice at all.

Overall, 55 of the 116 legislative seats are uncontested on the ballot. In 2010, before redistricting, only 24 seats lacked general election rivals.