But there are now 20 Republicans and 12 Democrats and of the 12 Democrats, 3 are Anglo, 3 are African-American, and 6 are Latino.

However, using the districts resulting from the “shortest-splitline” algorithm, I have compiled statistics and find that:

21 districts are Republican (18 strongly so)
2 districts are politically competitive
1 district is Anglo-Democratic
3 districts are ethnically mixed Democratic and
5 districts are Latino-Democratic.

So by the “neutral” algorithmic approach, Republicans should be doing better than they are at present. If we divvy up the two competitive seats among the parties, we might expect a 22-10 margin. What one must understand is that African-American districts and Latino districts must often be deliberately gerrymandered into existence – which is one reason geometric algorithms will never pass muster from a voting rights perspective.

Texas used to be solidly Democratic, until in the 80′s and 90′s Republicans overtook Democrats in sheer numbers of voters. In 1991, the voters in Texas were split nearly 50-50, but the Democrats still controlled both branches of the legislature and eked out the governor’s chair. How fair was the Democrat’s Congressional plan? Of 30 seats, the plan was drawn to elect 22 Democrats and 8 Republicans (although the final tally was 21-9 because one Democrat, Albert Bustamante, lost because he was embroiled in FBI corruption charges). So with just over 50% of the voters, Democrats passed a plan designed for some 73% of the seats. This was accomplished with some rather creative gerrymandering to elect many more Democrats than proportionality might warrant.

In 2003, Republicans were much stronger in voting base than the Democrats in 1991, about 56% of the voters. Of the then 32 available seats, the plan was intended to elect 22 Republicans, or about 69% of the seats (the eventual count was 21-11 due to a hard-fought campaign by Chet Edwards to hold his seat).

So it seems the 1991 Democrats were overreaching more that the 2003 Republicans in Texas in order to gerrymander in their favor. It’s just that in 2003 the Republicans were flipping from long-time Democrat dominance, so a number of Democratic incumbents were actually targeted for defeat.

Brilliant! Nice analysis – thanks!