State Partisan Control, 2005-2019

[Oryxslayer]

In the next two years I could see Arizona, Minnesota, and Virginia flipping to Dem trifectas.

Texas House and Florida Senate should both be in play for 2020 as well.  

Other than that I don't see much changing (Not sure about North Carolina's legislative chambers...?).  

Ducey is the governor, so it can't flip to a Democratic trifecta.

IMO the Dems have a good shot in 2020 at flipping the AK House, AZ House+Senate, FL Senate (crucial for redistricting), IA House, MI House, MN Senate, NC House+Senate, PA House+Senate, TX House, and WI Senate, and can conceivably break R supermajorities in the OH House and the KS House.

I mean, if the Democrats couldn't flip the big midwest chambers in 2018 when they are up by 8% nationally, why would they make some big gains in 2020 when the margin will be closer?

I mean, heres a basic rundown of the chambers:

 Alaska - this ones weird, and politics seems to be less based on Party ID and instead more parochial interests and cross-party pacts to form governing majorities. So I doubt a majority will be formed against the governor, but I admit I know little of AK poltiics.

Arizona - Definitely a dem target in 2020, the state house is probably more tempting then the state sentate.

FL Sen - I mean...how? Dems needed another pickup in 2018 to probably put the chamber in play, just looking at the map. 9 and 39 are the obvious targets, but then Dems need one more to tie (without a breaker), two to take. The route either goes through the pubbish SW with 21/23 or the increasingly Trumpish Treasure coast with 25. Considering how FL consistently bucks national trends, it would require a miracle to flip 3, when the third is going to be a lift.

GA House: More targets, but the ATL suburbs will still be a hard lift, since dems got most of the low hanging fruit in 2018. Chance of flip will be low.

IA house - Definitely a Dem target, but this one feels like a "missed in 2018, can't in 2020." Dems still are defending more trump turf, and pubs could easily go on offense here.

KS - Whats going to make this hard is that the dem targets are mostly moderate R's who would help bust the radical R's control. So, hard to say.

MI House - Really a case of missed in 2018, might not in 2020. Dems even went backwards in the Upper Peninsula. Still available though, but it will require a similar margin to sweep the surburbs for more dem pickups there.

MN Senate - Gimmi.

NC House+Senate - We really have no idea if new maps are happening, if not, Dems can only hope to hold the Pubs below supermajority.

PA: A case of "missed in 2018, so why 2020." Yeah, there are still more suburbs available, but dems still have more seats to lose, like in MI. Dems in the senate for example need 4 for a tied majority and in 2020 there is only one Philly suburb pub, a open seat in Allegheny, and Erie which are easy-ish pickups. But then you need to start guessing at gerryed seats like Lancaster's 13 or Dauphine's 15. Similar to the state house, dems need to punch through more gerryed seats.

They likely need to wait for 2020 redistricting .

TX State House: Easily in the Cards since Beto carried a majority of seats while losing by 48%. Dems could probably get away with 47 or 46% loss to flip, if that 47/46% is distributed efficiently. If you can flip a chamber while losing then that is a prime target.

WI Senate: Dems had good targets in 2018, but failed. They even lost a special election seat. Once again dems need to wait for the fair redistricting.

VA: Gimmi

[Oryxslayer]

An interesting measure might be district errosity over time. For example, is this really partisanship at play? Or did perhaps the 2010 cycle produce a bunch of Pub and Dem local maps that push states towards one unified type of government. I suspect the facts might be somewhere in between, after one examines just a handful of legislatures.

[Oryxslayer]

An interesting measure might be district errosity over time. For example, is this really partisanship at play? Or did perhaps the 2010 cycle produce a bunch of Pub and Dem local maps that push states towards one unified type of government. I suspect the facts might be somewhere in between, after one examines just a handful of legislatures.

I mean, yeah, gerrymandering definitely played a role, and it's pretty likely that at least a few more States (out of, say, WI, MI, PA, NC) would have split legislatures if it weren't for it. Still, gerrymandering has been a thing for several decades, but the rise of unified government at the State level has been a pretty recent development. Besides, this explanation kind of begs the question, since enacting a gerrymander first requires united government.

I guess I should have been more clear,  I mean the rise of deep data gerrymanders, made possible by modern computer programs with electoral data and tools going back centuries. The kind of software the allows one to draw a Republican district that resembles nothing except Donald Kicking Goofy from two democratic counties. And it really doesn't need to be unified control, as shown by NY where the state house map was gerryed to produce a dem supermajority, and state senate map gerryed to produce a republican majority. In this case, the gerry wanted to produce divided govt. If we accept that the deep-data gerry is new, then there is a theory that state reps could win a majority under 'fairer' gerryed lines (whatever that means) drawn by the opposition because they lacked deep data, and then draw deep data lines to reinforce their new majority. But beyond that yes, it does lead to a chicken and egg scenario which is why I suspect Gerry's are working alongside other factors like the polarization demonstrated above and decline of split ticketing.