In Wisconsin, Republicans maintained a 60+% advantage, entirely by partisan gerrymandering, despite barely clearing 50% of the vote. They're trying to expand that discrepancy, but I think the voters are tiring of it. Incumbency, however, has advantages (even illicit ones).
The US electorate is turning bluer, but its representation does not reflect that. Much of that is because of Constitutional structures, but the remainder is manipulation. At best, removing the manipulation will change the bias by a couple of percentage points, but about 3% of it is immune because of Constitutional mismatches. It will take decades of demographic and attitudinal change to flip that, but once it does it will be profound and lasting. Unfortunately, the damage inflicted in the interim will also be lasting.
