Friday, August 28, 2009
I've just uploaded a change that allows the application to use voting districts in addition to block groups, as the building blocks for drawing redistricting maps. This is a step toward getting partison data (specifically the 2008 presidential vote) into the app, because voting district partisan data is available for many states. That will require a bit more work, but will be coming soon. I've added 6 new states, all using voting districts: Alabama, Colorado, Illinois, Maryland, Mississippi and Virginia. I added voting districts to the existing state Georgia, so it supports both. If you have saved DRFs, you'll need to keep using block groups on those files. (Also, New York was added last month...) Check it out at Daves Redistricting. Enjoy.
Friday, June 12, 2009
Just a quick diary here to let you know I've enabled 6 more states (as of last weekend) for my free redistricting web application. They are Indiana, Louisiana, Massachusetts, Nevada, North Carolina and South Carolina. Next I plan to tackle PA and NY, which are time consuming because of the large amount of data. Thank you for your feedback on my previous diary a couple of weeks ago. Open Redistricting was one of the top feedback items. I've talked to Travis Crum, the person who proposed the Open Redistricting Project (via a Heather Gerken post on Balkanization -- my bad crediting Ms. Gerken) and we are exploring how to collaborate. So stay tuned. Getting political data was also quite popular, but I haven't figured out how to do this consistently. It may end up being part of Open Redistricting, where different individuals can contribute that data in some way. Another item from your feedback is to include a way to prepopulate with current CDs. That should not be too hard to do, so I will try to add that feature in a month or so. You may have already seen this, but andgarden at Swing State did a nice NJ redistricting map. Quick not on the 2008 population estimates. The Census Bureau gives those out by county. I take the additional population (or population loss) for each demographic group and distribute across the census blocks (really census block groups) in the county comensurate with the size of those demographic groups in each block. So it's as if the population grew by the same percentage in each census block. I also make sure that every additional person is the data is accounted for by taking any left over by rounding and adjusting the largest census block accordingly. Cross posted at Daily Kos. Thanks.
Wednesday, May 27, 2009
The free congressional redistricting web application I launched a few weeks ago now supports 12 states. These are Arizona, Florida, Georgia, Iowa, Michigan, Minnesota, Missouri, New Jersey, Ohio, Oregon, Texas and Washington. Also, the app now has 2008 population estimates. You can find the app here. I will continue to add new states (and make minor fixes) over the next month or so, in order to include all states that may gain or lose congressional seats. After that...what do you think? A number of people thru comments and emails have made suggestions on where to go with this tool. I don't have a ton of time to spend on it, but I want to keep it moving in a useful direction. Some of the suggestions include:
- Expand the number of districts so that the tool could be used for state legislatures; or better yet, support state legislative redistricting more fully by showing existing districts' shapes.
- Make this an open source project that could perhaps become an Open Redistricting Project as written about by Heather K. Gerken. The idea here is to enable citizen activists or commissions to do "shadow redistricting" and thus pressure the powers that be into staying in line.
- Have an option to color according to existing districts as a starting point.
- Add political data for districts. This may be difficult to do for some states.
And a couple of my own ideas:
- Figure out a way to get rid of the extra Windows app to make JPGs.
- Port from C#/Silverlight to Java/Flash and add in Google Maps.
What do you think? Thanks a lot.
Tuesday, May 5, 2009
I'm nervous about releasing this into the wild. There are bugs, but I think it's good enough now to let you all check it out. So, as promised a few days ago, here is my Redistricting App. With it you can create congressional districts the way you think they should be. It currently only supports Florida, Texas and Washington, but I'll get more states on line soon, especially those that stand to gain or lose seats after 2010. My last 2 diaries show examples of what you can do with the tool. The Redistricting App page gives a quick rundown of the features and a link to a more detailed Help page. Main Features include:
- Select state and number of congressional districts (CDs)
- Use mouse to sweep across map and assign block groups to CDs (block groups usually contain about 4 voting districts; using the larger size makes things more manageable)
- Save/Open your work in XML (saved in isolated storage)
- Use 2000 census numbers or updated census estimates
- Show/Unshow city, county and old CDs
- Create area maps of zoomed in areas
- Save state and area maps in XML (Separate Windows app can read this and produce JPGs; Silverlight won't allowing saving as JPGs directly; an app is available for download; XML schema also is available)
- Requires Silverlight 2.0 (runs on Windows and Mac)
- To get JPGs you have to run a separate Windows-only tool, due to limitations in Silverlight. Check the help page for more details.
- Loading data for a state from the server is slow, because the data is large, but after that the app is fast and does not go back to the server.
Friday, May 1, 2009
With the likely passage of a bill creating 2 more congressional districts (1 for DC and the other into the mix), it’s possible Washington State could get a 10th CD. Democrats current hold a 6-3 advantage among Washington’s House members. The 6 Democratic seats have been pretty safe in recent years, although WA-03 (Brian Baird) used to be more of a toss-up. Two of the Republican seats take up all of Eastern Washington (east of the Cascade Mountains) and are pretty safe. The other, of course, is WA-08, which covers part of the Seattle-Tacoma suburbs and exurbs, where Dave Reichert (R) defeated Netroots heroine Darcy Burner twice by slim margins. So, with a tenth district thrown into the mix could Democrats gain a 7-3 or even 8-2 advantage? To explore this question, I built a 10-CD map of Washington State, using a software tool I’ve been working on (and you can get, too). First a note on the tool: Next week I’m releasing this easy-to-use web tool for free for anyone to play redistricting. It currently supports Florida, Texas and Washington. I’ll be bringing other states online in subsequent weeks. Check back Monday for a diary on the tool. It uses 2000 U.S. Census Bureau data plus 2007 population estimates (by county). Could Democrats gain an 8-2 advantage? Unlikely for a couple of reasons: Washington has a bipartisan commission that draws the maps. Typically this means incumbent preservation and a reasonably balanced approach to making changes. Also, WA-04 and WA-05 (safe R districts) would shrink in size, leaving a significant area east of the Cascades that would have to be added to other districts. (They used to include all of Okanogan, Chelan and Kittitas counties. Check out WA 2008 Election Results Map to get a feel for what parts of the state are more progressive or conservative.) If too much of eastern Washington were added to WA-03, for example, that could flip to an R. A possible scenario, especially if Dave Reichert (WA-08 R) wins reelection in 2010, is that WA-08 becomes a safer R seat in exchange for a new WA-10 that provides a D advantage, while all other incumbents are protected. This is the map that I’ve drawn. As you can see, I’ve preserved part of the WA-08 base in south King County (where Reichert lives) and eastern Pierce County. But I’ve taken away the “high-tech” suburban areas of Mercer Island, Bellevue, Issaquah, Sammamish and Redmond. WA-08 would still retain the I-90 corridor (Snoqualmie, North Bend) and then jump over the Cascades at Snoqualmie Pass (I-90) to Kittitas County. From there the district follows US 97 over Blewett Pass through Chelan County and up to Okanogan County. (The magenta line is the old CD.) The new WA-10 would become the “high-tech” district including those cities formerly in WA-08 plus Kirkland, Woodinville, Renton and parts of Bothell and SeaTac. (If Darcy tried again in this district, she would have a great chance!) In other areas, districts 1, 2 and 7 remain largely the same. WA-01 (Jay Inslee-D) would creep further into north Seattle and take a little from WA-02 (Rick Larsen-D), while giving up Kirkland and Woodinville to WA-10. WA-09 (Adam Smith-D) would become more compact, centered on Tacoma and would become an even safer D. WA-09 would take away Democratic support from WA-06 (Norm Dicks-D). WA-06 would pick up part of Kitsap county, part of Olympia (a strong D area), but also Chehalis and Centralia (Lewis County), which are more conservative. We could give some of Tacoma back to WA-06, but then the Lewis County areas would pretty much have to go to WA-03, making it more of a risk to Democrats. For WA-03, this plan would probably be a wash. It would lose conservative Chehalis and Centralia, but also lose perhaps a little more of Democratic Olympia than it gains. It loses Pacific, Wahkiakum and Skamania Counties, but they total only about 18,000 voters (2008 election) We'll have to wait until 2011 to see what really happens, but this is one idea of might transpire. Check back next week for information on the tool if you want to try your hand at redistricting Washington State (or Texas or Florida), and I promise I'll get the census data for other states that stand to gain or lose sometime in the near future.
Friday, March 6, 2009
Brownsox wrote Sunday about the Fair Districts Florida initiative that is gathering signatures now (A New Hope For Redistricting in Florida). I wrote about this, too, in my last post. So I worked up a congressional district map (with the current 25 districts), to see what fair districts might look like. Here's what I came up with: Click to see it full size. First, the methodology: I've written a web application (soon available for everyone on the web for free) that allows you to create the congressional districts as you want. It's built using Silverlight (Microsoft's Flash-like software). I've used the 2000 census data (population broken down by ethnicity) for census block groups, which are a little bigger than voting districts. For Florida, I simply started in the northwest and worked my way down. I tried my best to keep counties together and to keep smaller cities together. Also, I tried to keep larger cities in as few chunks as possible. And I used no partisan data (which I don't have anyway). This follows the Fair Districts Florida guidelines which say
(1) No apportionment plan or individual district shall be drawn with the intent to favor or disfavor a political party or an incumbent; and districts shall not be drawn with the intent or result of denying or abridging the equal opportunity of racial or language minorities to participate In the political process or to diminish their ability to elect representatives of their choice; and districts shall consist of contiguous territory. (2) Unless compliance with the standards in this subsection conflicts with the standards in subsection (1) or with federal law, districts shall be as nearly equal in population as is practicable; districts shall be compact; and districts shall, where feasible, utilize existing political and geographical boundaries.The largest deviation any districts has from the average size is 699 people, which is a little more than .1%. Not bad, especially using the larger census block groups. Now, here's what the current districts look like (National Atlas PDF). There are so many differences. Since I do not have voting data for the census block groups, I can't do a more precise analysis on how this would change the congressional makeup, but here are a few comments on areas where my new map is very different and may open up more competetive opportunities: -- CD 3 is entirely in Duval County, the Jacksonville area, instead snaking all the way down to Orlando. Should still be a safe Dem seat. -- Tampa area: currently there are 2 Reps (old CDs 9 and 10) and 1 Dem (old CD 11, which is packed with both the heart of St, Pete and Tampa. In my more sensible districting, St. Pete and Clearwater are have 1 district (CD 13) and most of Tampa is in another (CD 12), both of which would likely be Dem. -- Around Orlando, Seminole County is within only 1 district. Then Orange County is split between 2 districts. Dems have 2 of the districts in that area already (old CDs 8 and 24); perhaps this would give us an opportunity to get another seat (new CDs 6, 8 and 9). -- Around Miami, Ft. Lauderdale and Palm Beach, the new map keeps counties and cities much more together. Reps have 3 districts (old CDs 18, 21 and 25). Mostly likely the new map does not help Dems with at least 2 of those (new 24 and 25), but could facilitate picking up 1 seat in the area. -- Note on Hendry County: it looks odd because the census block groups is very large in area. With the finer grain of voting districts, this could be smoothed out. In any case, though, there are not that many people in that county. Now, I have to admit that the language in the petition is vague enough that those in control will still be able to bend the process in their direction. So, we won't necessarily see maps as straight forward, and non-partisan, as this. But it will be a lot better than what we have now. I expect to have my app available within a month, with a lot more states, so you can try this on your own. That's all for now. Thanks.
Friday, February 13, 2009
Two Florida constitutional amendment petitions that would restrict gerrymandering are gathering signatures until October 2009. One for congress; the other for the legislature. They need 676,811 signatures to get on the November 2010 ballot. If successful this would result in a significant redrawing of the districts in 2011. Florida will likely get 1 additional congressional seat, too. FairDistrictsFlorida.org is sponsoring the amendments. The Florida Supreme Court recently ruled against those attempting to block the petitions. As I wrote in my previous post, Florida is one of the few large states where the distribution of seats between Dems and Reps is more than 1 seat away from what we might expect. Look at the district maps to see how seriously gerrymandered they are. So, Floridians, sign the petitions, collect signatures, do what you can. And if you know anyone in Florida...this is a great step in the right direction. NationalAtlas.gov has great maps of the congressional districts. Here's the PDF for Florida (800KB), which you can pan and zoom. Some of the districts are incredible (check out FL-16 (the Foley-Mahoney-Rooney district) or FL-23 (which Alcee Hastings (D) won with 82%)). So what would the constitutional amendment regarding congressional districts do? The ballot summary is
Congressional districts or districting plans may not be drawn to favor or disfavor an incumbent or political party. Districts shall not be drawn to deny racial or language minorities the equal opportunity to participate in the political process and elect representatives of their choice. Districts must be contiguous. Unless otherwise required, districts must be compact, as equal in population as feasible, and where feasible must make use of existing city, county and geographical boundaries.And the main text is actually short and very readable.
(1) No apportionment plan or individual district shall be drawn with the intent to favor or disfavor a political party or an incumbent; and districts shall not be drawn with the intent or result of denying or abridging the equal opportunity of racial or language minorities to participate In the political process or to diminish their ability to elect representatives of their choice; and districts shall consist of contiguous territory. (2) Unless compliance with the standards in this subsection conflicts with the standards in subsection (1) or with federal law, districts shall be as nearly equal in population as is practicable; districts shall be compact; and districts shall, where feasible, utilize existing political and geographical boundaries.A key point here is that the legislature is still responsible for producing a plan; no commision. But they will be much more constrained than before. From my perspective, there is still a lot of flexibility and therefore opportunity for the legislators to play favorites. However, there will be a lot less opportunity than there is today. If this passes and passes any legal challenges, I'm sure we'll see challenges to whatever plan the legislature comes up with in 2011.