And you can play along at home!
First, go to this website. It's a great resource for the public to be able to do their own Congressional redistricting.
Once you have gone there and made sure your Silverlight is up to date, Download this file and save it to your desktop. That is a shape file of every precinct in the state, which I filled in yesterday with the precinct breakdowns for every current Virginia Senate District. This is somewhat complicated- VPAP has great maps on their site, but they include split precincts on multiple maps, so I had to use the SBE and the 2000 lines to allocate split precincts into one district or the other for this exercise.
Now, let me explain how this works. Once you download my file, go to the website above and click on "open" in the upper left hand corner, and then open my file from your desktop onto the system. Once it uploads (may take a couple minutes) you will see each of the current Virginia Senate Districts on the map. You can zoom in and out as with any google map based system. On the left side, you can see population and whether the district is too large or too small. If you click on an individual district the demographics of that district will pop up on the right hand side. Just click on the big green "color districts" button on the right side to start changing lines.
As you scroll over each precinct you will see a pop up on the right with the demographics for that precinct as well as the Presidential voting percentages along with a party vote average from major elections. (When you look at an entire district those political numbers are a little off- I think they are averaging the averages of the precincts instead of calculating real votes, so don't follow that too closely. The demographic numbers are fine).
Here's a few tips as you start looking at this data:
1) Try to keep districts within a 2% margin of error rate (no smaller than 196,000, no larger than 204,000).
2) Try to keep clear communities of interest together and respect county lines when possible.
3) Try not to draw districts on opposite sides of water without a bridge to connect them.
4) To comply with the Voting Rights act make sure the 2nd, 5th, 9th, 16th, 18th stay above 50% African American with the over 18 population.
5) Finally, please draw Mark Herring into Maryland and reunite Dave Marsden with his wife in Signal Hill precinct.
Final rule: Have fun!