Redistricting-Mania: A Massive Look at Electoral Geography

Early in the new year, the Clerk of the US House of Representatives presents the results of the Census reapportionment to the Governors of the several states. As always, this will trigger congressional redistricting in each state. For the truly politics-obsessed among us, a fascinating subplot the recent US elections was control over redistricting. GOP victories were perfectly timed to help them over the next decade. Going state-by-state, we can have a good idea what to expect from redistricting. Overall, we can expect some states to gain seats, others to lose them. Using the estimates found here and here, I'll assume these changes:

Gaining Seats:
Texas (4)
Utah
South Carolina
Florida
Arizona
Washington
Georgia
Nevada

Losing Seats:
Ohio (2)
New York
Pennsylvania
Michigan
Massachusetts
Illinois
Minnesota
Iowa
New Jersey
Louisiana

For many states, redistricting will have no impact on their congressional delegations. This is most obviously the case with respect to those states having only a single House member, but is also the case for many states with relatively few Congressmen.

At-Large States - No changes:
Alaska
Delaware
Montana
North Dakota
South Dakota
Vermont
Wyoming

Others to ignore:
Rhode Island
Nebraska
Kansas
Idaho
Hawaii

All the others have at least some interesting things to consider. The partisan makeup of every House district has been calculated by the Cook Political Report, called the Cook Partisan Voting Index (PVI), and can be found on Wikipedia. The control of the various state legislatures are found here. Looking at them one by one, I'll try and guess what redistricting may have in store.

Maine: Republican-controlled. At best, Republicans can hope to make one of the two congressional districts competitive for them. But both districts probably remain Democratic. No Change.

New Hampshire: While the Granite State just elected a Democratic governor, the State House & Senate are controlled by GOP super-majorities, cutting the Democrats out of redistricting. But New Hampshire only has two districts, both held by Republicans. Republicans have two options, given the partisan makeup of the state. New Hampshire has trended Democratic over the last decade, and the best long-term plan might be for the Republicans to strengthen one district at the expense of the other, perhaps relying on the power of incumbency to preserve Charlie Bass through a few cycles. But it is more likely that redistricting will change as little as possible, or even try to equalize the partisan composition of the districts, but overall, No Change.

Massachusetts: The Democrats wish their massive control over state government would help them here, but with all congressional districts held by Democrats, there is nothing to help. But Massachusetts does lose a seat in redistricting. Democrats -1

Connecticut: Democrat-Controlled. Redistricting will change ensure no seats become Republican-leaning, and may even make a few of them more Democratic. No Change.

New York: While it is still too early to say for certain, it looks like the Republicans will just barely recapture the State Senate, giving them a seat at the redistricting table. New York will lose a seat, and I assume that seat will be lost in upstate New York, the one area of Republican strength. Geographic limitations also come into play downstate: the Staten Island seat is awkward to redistrict away, so it will remain Republican-leaning. Redistricting may also push the 1st district into slightly more Republican territory, which will benefit the Republican currently leading. Overall, Republicans -1, perhaps -2.

New Jersey: New Jersey's redistricting is controlled by a independent commission, which will have to deal with losing a congressional district. The current delegation is split 7-6 for the Dems; it seems likely that in such a liberal state, a 7-5 split will be most likely. Republicans -1.

Pennsylvania: Republican-controlled, Pennsylvania will be losing a seat. This is perhaps the first really fascinating state for redistricting, as the GOP have a free hand to gerrymander. Pennsylvania is the wild west of congressional races: of the current 19 districts, 7 have Cook Partisan Voting Indices of less than +/- 5. Three Republican-leaning districts are represented by Democrats, while no fewer than five Democratic-leaning districts are represented by Republican congressmen. Overall, the Congressional delegation is 12-7 for the GOP. Redistricting will give the GOP the opportunity to weaken Democratic incumbents Mark Critz, Jason Altmire & Tim Holden, while strengthening the position of Republicans in swing districts. Pittsburgh currently has a single Democraticly-dominated district at its core, leaving GOP-leaning districts surrounding it. Philadelphia has two highly Democratic districts (D+35, D+38), but with a number of Democratic-leaning districts encompassing the suburbs. Concentrating liberal polls in one further district should allow the Republican incumbents to rest easier in their beds. Ideally, the GOP comes out of this redistricting cycle with a 14-4 edge, but 12-6 is perhaps more likely; it is hard to see how a competant gerrymander does worse. Let's say 13-5, giving Republicans +1, Democrats -2.

Maryland: On the other side of the Mason-Dixon, Maryland is controlled by the Democrats; but it is difficult to see how they eliminate either of the two Republican districts. No Change.

West Virginia: Democratic-controlled, but pretty homogenous, redistricting may weaken the advantages of incumbency, but likely will not alter the partisan balance. No Change.

Virginia: Mixed control, Virginia keeps its 11 seats, currently on a 8-3 split for the GOP. Incumbents will probably get a little more comfortable given the need for a bipartisan redistricting plan. No Change.

North Carolina: Probably the most impressively pro-Democratic gerrymander during the last cycle, this conservative state has a 7-6 Democratic delegation. The state has a Democratic Governor, but newly a newly Republican state legislature. According to Michael Barone, in North Carolina the Governor cannot veto redistricting bills. While a Southern state, North Carolina is not overwhelmingly Republican, with a PVI as a whole of only R+4. Democratic areas are fairly spread out. Nevertheless, I would expect that a Republican gerrymander would eliminate one Democratic districts and sufficiently weaken either Larry Kissell or Mike McIntyre in the south of the state to result in a 8-5 GOP delegation. Taking a look at the map, Larry Kissell looks more easily isolated from Democratic districts, and McIntyre could benefit from a significantly more Democratically-leaning district. GOP +2, Dem -2

South Carolina: Controlled by the GOP, the Palmetto state gains a congressional representative this cycle, who will add another member to the GOP delegation. GOP +1

Georgia: Another souther state controlled by the Republicans, Georgia has two Democratic incumbents in very narrowly Democratic districts. It also is gaining a seat this cycle. Redistricting will allow the GOP hand themselves the new seat and weaken both vulnerable Democrats significantly, ideally picking up two more seats. GOP +3, Dem -2

Florida: Hard to predict. Florida gains a seat, perhaps two, this cycle, and its state government is and will be controlled by the Republicans. But the state passed a constitutional amendment which will likely result in any redistricting plan to be fought in court. Fortunately for the GOP, the redistricting will still be instigated by the legislature, even presuming the amendments are upheld on a court challenge. My guess is that the judiciary will be loath to interfere too much, and that the GOP will, by and large, get the districts they want. However, the Florida delegation is already about as GOP-leaning as possible, and adding another GOP district is probably the best the elephants will get. GOP +1

Alabama & Mississippi: Both states have divided governments, both currently have congressional delegations with a single Democrat in a majority-black district. In neither state will matters change. No Change.

Louisiana: Mixed control, but it will hardly matter. No one could draw a remotely sane map in Louisiana that did not result in a Democratic district centred in New Orleans and GOP districts everywhere else. But as Louisiana will be losing a congressional seat, this means: GOP -1

Arkansas: Democratic-controlled, the redistricting process will change little here. All the districts will remain GOP-favoured, but this is prime Blue Dog territory. Mike Ross can sit pretty for as long as he likes, most probably. No Change.

Tennessee: Republican controlled, but already Republican-dominated. Democrats hold only two of the 9 seats, one each in Memphis and Nashville. The Memphis seat is safe to redistricting, but the GOP could try to weaken the Nashville seat. Nevertheless, the safest bet here is No Change.

Missouri: Missouri doesn't have many competitive seats. It also has split control, with a GOP legislature and a Democratic governor. The only seat redistricting could really switch is MO-3, which was just barely held this past election by Russ Carnahan. Nevertheless, it has a D+7 ranking, and probably won't be changing hands even if the GOP got their druthers. No Change.

Kentucky: With split control, it is unlikely anything will change here. Nevertheless, any changes to district boundaries will weaken Ben Chandler, a Blue Dog who barely survived last week. But let's be conservative, and say No Change.

Ohio: Ohio will be Republican-dominated again this cycle, as it loses two seats. Right now the congressional delegation is split 13-5 for the GOP. Republicans will be hard pressed to move it to a 12-4 split. Perhaps 13-3 is possible, but that would appear to be overly ambitious. GOP -1, Dem -1

Indiana: Another midwest state where the Republicans control redistricting. Democrats can look forward to being restricted to two seats: one centred on Indianapolis, the other on Gary. The resulting partisan balance will be 7-2 Republican. GOP +1, Dem -1.

Illinois: The sole midwest state controlled by the Democrats, Illinois could be a bit of a bloodbath for the GOP. With the current delegation at 11-8 for the GOP, 8-10 might be the best to be hoped for. GOP -3, Dem +2.

Michigan: Michigan, currently with a 9-6 GOP congressional delegation, will be losing a seat. Clever gerrymandering might allow just four Democratic districts, though that will probably result in a number of swing districts. But let's be optimistic. GOP +1, Dem -2.

Wisconsin: Another GOP-controlled redistricting, the GOP's best hope is to concentrate more Democratic votes into the Madison district, giving the GOP the edge in WI-3 and shoring up WI-7. Tough, but GOP +1, Dem -1.

Iowa: Iowa will lose a seat this cycle, taking it down to four. With a non-partisan redistricting board, it's hard to predict exactly what will happen, but I'll give the edge to an equal delegation, meaning that the Democrats will lose a member. Dem -1.

Minnesota: Also losing a representative, Minnesota has divided state control. The question is which party will lose the seat. Collin Peterson's seat is safe so long as he cares to run, it would seem, and there are at least two Twin Cities-area seats that are strongly Democratic. Minn-1, which is held by Democrat Tim Walz, is already Republican leaning (R+1) but Erik Paulsen in Minn-3 (Even) and newly-elected Chip Craavack in Minn-7 (D+3) are vulnerable. At a guess, Paulsen and Cravaack will get more Republican districts, while Walz becomes vulnerable (possibly facing John Kline in Minn-2). Such a result keeps things interesting, as a Walz-Kline contest would be very competitive. Assuming Craavack holds his district, this leaves a 4-3 Republican split. Dem -1.

Oklahoma: Five districts, all very conservative; one is represented by Dan Boren, a conservative Democrat. I don't suppose there will be the political will to try and eviscerate Boren's district, and he might well survive regardless. Redistricting will probably defer to the incumbents. No Change.

Texas: Texas is Republican-controlled, and stands to gain 4 seats. None of the surviving Democratic representatives are in Republican-leaning districts, and it may be difficult to eliminate any of them. However, there is a possibility to split Austin apart, and it may also be possible to concentrate Democratic votes along the Rio Grande, to make at least an extra district competitive. Overall, Rep +5, Dem -1.

New Mexico: New Mexico has only three Congressional seats. As a swing state, redistricting largely decides whether two seats lean Democratic or two lean Republican. With a Republican governor, and a Democratic legislature we can expect no alteration to the current order. No Change.

Colorado: Colorado is another state with divided partisan control, although the Democrats do look to have the stronger hand here. The state geography probably would make it difficult to carve out a fourth Democratic-leaning district regardless, so the delegation will likely remain 4-3 GOP. No Change.

Utah: Utah now has the distinction of harbouring the most out-of-place congressman in the US House. Jim Matheson's district is rated at R+15, narrowly edging out Dan Boren's Oklahoma district at R+14. However, Boren is pro-life, Matheson is not; Boren has a lifetime ACU rating of 52, Matheson of 40, so Matheson is substantially more mismatched. Redistricting Matheson out of a job should be job #1 for Utah Republicans. As Utah is adding a House seat, this is made even easier. The strongest option would be to redistrict Matheson into a contest against one of the Republican incumbents, but just depriving Matheson of his stronger areas could be enough to topple him. Nevertheless, Matheson is strongly entrenched, and could survive another round of redistricting. GOP +2.

Nevada: Nevada is gaining a seat, and, as a swing state under mixed control, will likely come up with a map that gives a fairly safe 2-2 distribution. Dem +1

Arizona: Arizona's redistricting is controlled by an independent commission, which will have to determine the placement of an additional district, as well as realigning the existing ones. Doubtless the additional district will be Republican, but it will be interesting to see if Gabrielle Gifford's district becomes more or less Republican. Rep +1.

California: During the last redistricting, California opted to entrench most of its incumbents. As a result, very few seats have changed hands over the past decade. California passed a ballot initiative this year establishing an independent commission to oversee redistricting, which will probably favour incumbents to a certain extent. Even though California is not gaining or losing seats, internal demographic changes will inevitably result in significant shifts in district lines. Exactly how this will effect the map overall I am not certain. However, it seems probable that urban, Democratic areas have increased in population. At a guess, Dem +2, Rep -2.

Oregon: Despite being a relatively moderate state (PVI D+4), Oregon has a 4-1 Democratic congressional delegation. However, this reflects a fairly basic division between the somewhat liberal coastal section of the state and a very conservative interior. With Republicans only having minimal power over redistricting (a tied State House), incumbents will likely see little alteration to their districts. No Change.

Washington: One of the few states with univocal Democratic control, Washington Democrats will not get the chance to use their power, as redistricting is determined by an independent commission in the state. Washington is gaining a seat this cycle, and given the partisan slant of the state as a whole, the extra seat will probably be Democratic. Redistricting may shift the partisan balance of some other seats significantly, as Washington has a fair number of comptetive districts. Dave Reichert's survival in the Democratic-leaning 8th district could be in jeopardy if he has to deal with a more liberal voter base. Nonetheless, the most likely outcome here is: Dem +1

Overall, I estimate a swing of 8-10 seats towards the Republicans solely because of redistricting this cycle. This is an estimate taken entirely outside of changing political circumstances- it is, in effect, an attempt to estimate what the result will be if 2012 sees the same voting patterns as this year.