In the seven Republican-controlled states, the total votes cast were 16.22 million (50.8%) for Republicans, 15.68 million (49.2%) for Democrats for a 74 R, 32 D outcome. The simulations indicate that this seat split would normally only require 11.7 million Democratic votes. In other words, 4 million Democratic voters in seven states were disenfranchised.
In Illinois, the total votes cast were 2.74 million (55.4%) for Democrats, 2.21 million (44.6%) for Republicans for a 12 D, 6 R outcome. In this case, 1.8 million Republican votes would have been “enough” to elect this delegation, so that about 400,000 Illinois Republican voters were disenfranchised.
Therefore the disenfranchisement due to partisan-controlled redistricting was a total of 4.4 million voters from both parties. Democrats were disenfranchised more than Republicans, at a ratio of 10:1.
I will conclude by saying that the problem of partisan gerrymandering has been identified as a major problem, both by nonpartisan Congressional scholars Mann and Ornstein (in book and column), and recently by partisan commenter David Atkins. The problem is finding a remedy. Republicans had an extremely lucky year in 2010, when they assumed control of a record number of legislatures – and therefore control over redistricting.