The end of gerrymandering in California

I’ve blogged a few times over the last couple of years about the perverse processes used in most US states when drawing electoral boundaries for Congress and state legislatures.

In a series of referendums in 2008 and 2010, California’s voters approved the creation of an independent commission to redraw California’s boundaries after the decennial census.

New boundaries will be used for the first time next week for the House of Representatives. The previous boundaries were used from 2002 to 2010 (and you can download Google Earth maps of those boundaries from this page), and the new boundary will be used until 2020.

California’s previous boundaries were drawn to ensure that incumbents, both Democrat and Republican, were able to retain their seats, and these boundaries were very successful in preventing competitive races over the last decade.

These boundaries were severely gerrymandered – jagged boundaries interlocking with each other and covering different areas. This was a similar style to other big states such as Florida and Texas, where districts are transparently designed to produce a particular result.

The new boundaries in California are completely different – seats tend to be far more compact – covering a much smaller geographic area and reflecting local communities. Looking at the new boundaries, it’s immediately obvious what a massive affect these changes have made.

The following maps show the old and new boundaries for the Los Angeles area and the San Francisco Bay area.

Congressional districts in the Los Angeles area, 2002-2010.

Congressional districts in the Los Angeles area, 2012.

Congressional districts in the San Francisco Bay area, 2002-2010.

Congressional districts in the San Francisco Bay area, 2012.

The new boundaries have already had some interesting effects, with incumbents running against each other.

California has also recently instituted the ‘jungle primary’ system, where all candidates from all parties compete in a single primary, and the top two candidates, regardless of party, proceed to the general election. This has meant that there will be a number of races this week where two sitting Democratic members of Congress will be running against each other for the same seat.