Seats in the US House of Representatives are allocated to each state once every 10 years, following the national census. The latest census, conducted last year, sees 12 seats change between states. Texas gains four districts, while Florida gains two. Ohio and New York each lose two seats. Eight states lose one seat each, while six states gain one seat.

This change has triggered a wave of redistributions (or redistricting, as it is called in the US) in the 43 states with more than one congressional seat. Last year’s mid-term election victories have given Republicans an upper hand in redistricting. Unlike in Australia, electoral boundaries are drawn by legislators, and they don’t shy away from exerting maximum political influence over the boundaries produced.

Legislators have a choice in how they gerrymander: they can make the seats of their incumbents safer or they can create more districts that their party can win. Republicans won a large victory at last year’s election, meaning that they have a lot of incumbents in seats that were previously Democratic who will be looking to be protected. If they are greedy and spread Republican votes out among more districts, they may lose several seats if the Democrats pick up a swing.

Three of the largest states in the US have the most interesting redistricting processes taking place now.

In Texas, Republicans have firm control of the redistricting process, but will find it hard to gain any ground in the process. Texas Republicans gained control of the Texas legislature in 2002 and proceeded to conduct an unprecedented mid-decade redistricting, which shifted the boundaries substantially towards the Republicans and saw several Democrats lose their seats in 2004.

Texas has gained four seats in the census largely due to its booming Hispanic population, who tend to vote Democratic. The federal Voting Rights Act will likely require Texas to create several new seats with a majority Hispanic population, which will probably be won by the Democrats. This does have a benefit for the Republicans: creating a heavily Democratic majority-minority district “locks up” many Democratic voters and makes it easier for neighbouring Republicans.

Texas

Florida has a reputation for heavily gerrymandered districts, which have given a substantial advantage to Republicans in a key swing state. At last year’s election, two referenda were passed that impose criteria for fairness and compactness on new boundaries being drawn for the House of Representatives and the state legislature.

It’s yet to be seen how stringently the courts will impose these rules on a partisan legislature. The rules could force the legislature to break up the majority African-American 3rd district. The district is heavily gerrymandered, connecting the black parts of Orlando and Jacksonville, 200 kilometres apart.

Florida

The sitting congresswoman, Corinne Brown, has railed against the changes, but they have been supported by the Democrats and the NAACP. Breaking up the district could improve chances for Democrats. Two Democratic members lost their seats in the Orlando area in 2010 while Brown’s district covered the strongest Democratic parts of the city.

Until now there have only been a small number of states that have independent redistricting commissions. This time around they will be joined by California with its 53 seats. California’s gerrymander is designed not so much to advantage the majority Democrats as to protect all incumbents and avoid the creation of marginal seats. In five House elections over the past decade, only one of California’s 53 seats has changed hands, once.

California

The new independent commission will likely see a complete redrawing of boundaries. Incumbent members of Congress will likely be forced to run against each other, while the number of competitive districts should increase on the new boundaries. For those campaigning to end gerrymandering in US elections, the change in California will be a big step forward.