2020 is the Election Democrats Should Really Be Focusing On.....

[Skill and Chance]

We also need to account for state legislative supermajorities and veto rules.  In the states shaded 60% for a party, that party would have the power to impose a redistricting plan against the will of the governor under that state's rules.  Green is a commission:

[Skill and Chance]

Now here is a realistic Democratic ceiling for 2021.  Would this be enough to make the House an even playing field?  It's remarkable to think that the all the dark blue states combined could contain as few as 10 D house seats.

[Skill and Chance]

Florida also has a commission.

Well, that's complicated.  I would say Florida is more like Michigan.  They both have stricter than normal rules on paper, but in practice it is possible for a party with full control to distort things more than a court would.  There are still only 8 D-PVI seats in Florida today.  If Democrats controlled the process there, they could probably get away with 14-15D/12-13R.  A court would probably draw 15-16R/11-12D.  Similarly, a court map in Michigan would surely have more than 5 Dem seats.

[Skill and Chance]

How about a majority Democrat-appointed SCOTUS overturning gerrymandering in 2018-2020?

The best thing for the country by far would be an extension of Baker v. Carr or Shaw v. Reno to require that all congressional/legislative districts be drawn without regard to partisanship.

[Skill and Chance]

This depressing map is now where redistricting prospects stand.  Grey states either have mixed control, are under an independent commission, or only have a single congressional district.

Connecticut has a 2/3rds requirement (which Dems don't have), and Hawaii has a commission.  But Massachusetts, Maryland and Illinois Dems can still override a veto, so they should be red.  West Virginia should be blue because they have simple-majority override and Republicans have both chambers.  Kentucky is also a simple majority state, so unless the lower house stays D for the decade, they will be able to gerrymander Yarmuth out in 2021.  And the supreme court is probably about to let Republicans redraw Arizona.  It's going to be a loooonnngggg decade for House Dems unless they get like a 61%/38% generic ballot in their favor.