California Redistricting with Google Fusion Tables

By Matt Stiles | | Topics: Uncategorized

This redistricting map app is among the best Google Fusion Tables examples I’ve seen in media. It draws proposed legislative boundaries but also has a nifty search function. Here’s the before/after view of congressional districts statewide:

Before/after Compton:

Before/after San Diego:

Before/after Los Angeles:

Nice work, LA Times.

Mapping Redistricting with jQuery Before/After

By Matt Stiles | | Topics: Uncategorized

Today’s viz from work uses the jQuery Before/After plugin to create sliders over static Texas House redistricting maps to visualize changes:

The Texas House approved new political maps last week as part of decennial redistricting. In many cases, the newly drawn state House districts changed boundaries so that Republicans could preserve their majority. Use this interactive map graphic the see the changes.

The Politics of Redistricting

By Matt Stiles | | Topics: Uncategorized

A cross-post from my work blog:

As state Sen. Kel Seliger said last week, the decennial process of drawing the boundaries around legislative districts is inherently political, a fact that’s apparent by looking at the maps themselves.

Take the case of state Rep. Aaron Peña, R-Edinburg, who followed his 2010 election as a Democrat last year by switching to the GOP, which now has the largest majority for either party since 1983.

In the statewide map proposed by the House’s redistricting chair, Rep. Burt Solomons, R-Carrollton, Peña’s district is redrawn to boost his chances for re-election as a Republican in Democrat-friendly Hidalgo County. First, this map shows current districts in the Rio Grande Valley. Peña is the lone Republican.

Here’s the proposed change. Notice the new district drops the northern, rural and sparsely populated portions of Hidalgo County, and the Sullivan City area in the far southwest corner along the border with Starr County and Mexico.

This thematic map shows voting tabulation districts — the U.S. Census Bureau’s version of a precinct — in Hidalgo County, and how they voted in the 2010 governor’s race. Darker shades represent stronger supoort for the Republican in the governor’s race. See how Peña’s proposed district now captures the more Republican-leaning areas.

The two voting districts in the far northwest portion of the county lean Republican, but they contain few voters. This map shows the raw vote totals for both parties during the 2010 governor’s race. Look at the GOP vote map again in the context of Peña’s current and proposed districts. You’ll see he traded high raw vote areas that lean Democratic in favor of those that lean Republican:

His district is also now changed demographically. The current district is 94 percent Hispanic. The proposed boundaries would lower that to 76 percent. Hidalgo County as a whole is 90 percent Hispanic, according to the census count.

Will it work, assuming these boundaries don’t change? We’ll see. In the end, it’s a numbers game. Peña’s current district voted 76 percent for Bill White, the Democrat who lost the governor’s race against Gov. Rick Perry. The governor won the proposed district with 50.1 percent of the vote.

Go here to download all the data used to make these maps. Let us know if you have feedback or ideas for other data-related content, and be sure to follow @TribData on Twitter for updates.