Most deceptive gerrymander?

[muon2]

Despite Daniels vows to make redistricting fair to both sides, I think Republicans are going to benefit heavily from it.
The district on the left is the current and on the right is the proposed.


This, in my opinion, is as fair as it's going to get. If Baron Hill survives in 2010, he'll have an even tough time in 2012. Same with Joe Donnelly. The new map favors 7 Republicans and only 2 Democrats. Parts of current heavy-Republican districts are being moved to the battlegrounds, which in the end will make no district 100% safe like some currently are, but will give 7 districts a Republican edge.

Don't they usual wait until they get the census data to make a new map?

No. In all 50 states, both sides already have draft maps. You can buy estimate data to the block-level and state parties do. Of course the official map has to wait for official numbers, but drafts give a good idea of the direction that a party should pursue.

[muon2]

No. In all 50 states, both sides already have draft maps. You can buy estimate data to the block-level and state parties do. Of course the official map has to wait for official numbers, but drafts give a good idea of the direction that a party should pursue.

What are the estimates based on?  ACS PUMS?

The 5-year ACS to the block group level will be released this December.

The public estimates for 2009 at the county and place level can also be acquired at the block level for use in GIS redistricting programs. I doesn't look like it's just an even spread of the high level data. I'll have to see if I can identify the provenance of the data.

[muon2]

Well, no. It's more that concentrated strength makes it easier to gerrymander effectively.

Well, specifically in the case of Michigan, community of interest considerations would certainly create the two Black seats and probably Sander Levin's too - though very little else of the state would look anything like it does now.

Really? I'd say all of the following are pretty natural from a "communities of interest" point of view:
- putting the UP district down the more blue-collar eastern half of the LP rather than the summer playgrounds around Traverse City
- a district for the Thumb
- a district for Flint/Saginaw
- an affluent Oakland district - granted, Pontiac is out of place, but Pontiac will be out of place anywhere unless you do a snake up to Flint which would be even more of a GOP gerrymander.

And then there isn't anything obviously disastrous about west Michigan. I agree that the Lansing district and the Ann Arbor/Dingell combination are clearly gerrymandered, but Michigan is going to have more GOP seats than the popular vote would dictate in pretty much any district-based FPTP system unless you give Detroit the fajita treatment.

Mathematically MI averages about 53% D to 47% R. The two black-majority districts average about 85% D. If there are 15 districts, as there were in the last cycle, then that leaves the remaining 13 districts at 47% D to 53% R. A fair division would create a 7R - 6D split of these districts for a total 8D - 7R delegation.

The actual map used a state law requiring that county (and other municipal) splits be minimized, but the requirement was loose enough that a 9R - 6D map was approved by the partisan legislature. However, as the map was slanted, many of the R seats were competitive and have changed hands over the decade, such that the delegation is now 8D - 7R as one would expect with a fair split based on statewide voting tendencies.

[muon2]

They're not really reasonable, though. They're drawn to dilute Democratic strength.

- MI-03 puts Grand Rapids in the very western corner. A fair district would have Grand Rapids as the center of population.

- MI-04 is specifically drawn to exclude Saginaw, and stretches 2/3rds of the way across the state.

- MI-07 and MI-08 each stretch from the middle of the state to the suburbs of Detroit. Battle Creek and Lansing would more logically be put in the same district, but they're split between the two.

- MI-11 is a bizarre L-shaped district that also attempts to dilute Dem strength as much as possible.

What is interesting about this observation is that MI used fairly rigorous standards to draw districts in 2001. They were based on the standards used by the court-appointed master in 1981 and 1991 and codified into law in the late '90s. The standards rest heavily on minimizing the splitting of counties, townships and municipalities, and the law describes the types of splits that are permissible.

An analysis for the Midwest Democracy Network by Michael McDonald of George Mason U last year showed that the partisan composition of the districts had 5 strong D, 2 strong R and 8 lean R. The fact that the GOP was able to stay within these standards to get an such effective advantage perhaps does rank MI as the most deceptive gerrymander.

To satisfy my own curiosity, I tested the MI standards with the estimated data set. All districts are with 100 persons of the ideal size, and two black-majority districts (58% and 56%) are maintained. The districts were drawn to conform with MI state law as regards to minimization of county, township and municipality splits. Using 2004 presidential votes, I get 5 strong D districts, 4 strong R, 2 lean D and 3 lean R. Based on this I would conclude that the standards were fine, but not tight enough to prevent partisan gerrymandering.


 

[muon2]

There's also Idaho. Yes, Idaho. You may wonder how you can gerrymander a super-Republican state with only two districts, but they basically did this by splitting Boise right down the middle, clearly to prevent the possibility of any strong Boise-based Democrat taking a seat on their own merits. Succeeded in that sense but failed in preventing district 1 Republicans from nominating Bill Sali. However it does make me wonder if all of Boise will be removed from ID-01 in redistricting. This will put pretty much all the areas with a notable number of Democrats in Idaho in one district, but also plenty of Mormons and probably enough to cancel them out.

It is pretty hard to keep Boise in a single district unless you want to have a district that includes Eastern Idaho and the panhandle.

That type of map could look good on paper, but the two parts would have little or no road connection without going through MT. When ID gets a third district it should divide quite nicely.