I know on another thread we have been discussing the possibility that the republicans hold the house but loose the house popular vote by 4-6 points (IMO the most likely outcome of the 2018 election, I think they will keep the Senate as well).
This is a story about the information used to declare NC's legislative map unconstitutional via partisan gerrymandering.
http://wunc.org/post/non-partisan-redistricting-possible-former-judge-and-mathematician-think-soAnd if you are interested the link to the Duke math department's blog about this.
https://sites.duke.edu/quantifyinggerrymandering/Basically a professor in the Duke math department came up with a way to analyze voting maps that shows that the map drawn by the NC legislature was an outlier that showed gerrymandering. The same type of analysis shows Maryland was gerrymandered for the dems as well.
If the supreme court allows this type of mathematical analysis to declare when a map is unfair, it probably won't come soon enough to change 2018 but 2020 could see a big shift.