Bob -- there are a number of ways "accountability" legislators could be chosen. It could be, as you suggest, through some sort of "party endorsement" process whereby the party "worker-bees" choose them. They could also be chosen by the voters, the same as the district candidates. It could be done statewide where voters essentially rank-order a list of candidates who would get seats according to their vote total. It could also be done in consolidated "accountability districts" with each consolidated district getting one accountability seat. Using a traditional voting-rights method like limited voting would give minority candidates a better chance of winning accountability seats.
As to which party is the more egregious gerrymanderer, it's not about whose districts are more misshapen, divide counties/towns/precincts, etc. Both parties have done plenty of that. The true measure is how much a gerrymandered plan gives the party in power undeserved seats. During the five elections from 2002 through 2010 when the maps were drawn by Democrats, the discrepancy between Democratic votes and undeserved legislative seats averaged 5.5 percentage points. Under the 2012 Republican-drawn plan, the discrepancy was 13 points between Republican votes and undeserved legislative seats and 20 points for undeserved congressional seats.
Gerrymandering is used by the party in power to gain undeserved control without necessarily winning more votes. In the 2012 congressional elections, Democratic candidates won 50.6% of the statewide vote but only 4 of 13 congressional seats (31%). In legislative elections, the vote split was 52%-48% for Republicans. But Republicans won 65% of the General Assembly's 170 seats. In past decades, Democrats used gerrymandering to cement their control while not always winning more votes. But current Republican gerrymandering (as measured by the ratio of votes to seats) is considerably more egregious.
The redistricting quagmire could be ended once and for all with a simple solution that's fair to both sides. Ninety-percent of legislators would be elected from districts; the other 10 percent of seats (12 House, 5 Senate) could be chosen at-large. These "accountability" seats would be used to reconcile the discrepancy between a party's statewide vote and the seats it gets in the legislature. In state House elections, for example, if a party won 50 of the 108 district seats (46%) and 51% of the statewide vote, then 11 of the party's "accountability" candidates would get seats (50 + 11 = 61 seats).
The "accountability" members could be chosen statewide or from regional consolidated districts. Top vote-getters in each party would get their party's share of "accountability" seats. It's a method similar to how the parliaments of Germany, New Zealand and Scotland are elected. Politicians on both sides need to stop manipulating their way to power through gerrymandering and allow voters to decide who controls the legislature.
Re: “Judges should strike down GOP redistricting”
Bob -- There's no question Republicans are subverting the Voting Rights Act intent of "enhancing the ability of minority voters to elect representatives of their choice." It's unfortunate that the way the VRA has been implemented -- to an extent -- has facilitated a Republican strategy of dividing black and white Democrats and gained the GOP undeserved political advantage. Even with the increased number of African-Americans you cite (22 in the House, 7 in the Senate), African-Americans, and racial minorities in general, are still significantly under-represented in lawmaking bodies. Exclusive reliance on single-member districts drawn with specific percentages of minority voters has constrained minorities from mobilizing their full voting strength. Hopefully, we're seeing a new phase where black, brown and white progressives are unifying to achieve fair representation for everyone.