If you're the type who falls asleep instantly upon hearing the word "redistricting," consider the country's most famous beneficiary of the process: Barack Obama.

Before he was president—before he was even a U.S. senator—Obama was a lowly two-term state senator from Chicago whose only attempt at higher office, a run for Congress in 2000, had resulted in him getting bounced out of the primary by an incumbent, Democrat Bobby Rush, who liked to say things like "Barack Obama went to Harvard and became an educated fool."

Then, as recounted by New Yorker writer Ryan Lizza in "Making It," the definitive 2008 article on Obama's rise in Chicago, the future president learned a thing or two about redistricting (a process that's now poised to bring Washington State a new seat in Congress). The year after losing his bid for Congress, Obama went down into a highly secured "inner sanctum" below the Illinois State Capitol building with a political consultant who ordered up some detailed maps of Chicago and, as Lizza described, "sat in front of a terminal to draw Obama a new district."

A lucky fluke of timing and political geography allowed Obama to do this. The 2000 census had just come in, and, as required every 10 years by the Constitution, districts around the country were being redrawn to reflect the new population count. Plus, Obama lived in Illinois, where, controversially, the party that controls the state legislature is allowed to control the redistricting process. The result was that the future president ended up with a newly drawn state legislative district that had more money and a more diverse constituency, which turned out to be the perfect platform from which to launch his second attempt at higher office, his successful 2004 campaign for U.S. Senate.

The rest is history.

We're now coming up on the next national opportunity for politicians—and, hopefully, the public—to benefit from the once-a-decade rejiggering of America's political maps. The 2010 census is under way, and after its results are in later this year, states around the country will set about redrawing their districts to reflect shifts in population (the most basic goal is to make sure all similar districts represent an equal number of people—for example, after the 2000 census, the congressional districts in Washington were all reconfigured so that they each held about 655,000 people).

Some of the country's fastest-growing states will also have the delightful job of squeezing in a brand-new congressional district. Washington State, experts are predicting, will be one of them. (Among the slow-growing states predicted to lose seats in the process: Ohio, Louisiana, and Massachusetts.)

For nonwonks, here's the background on why: There are a total of 435 seats in the U.S. House of Representatives. Every state gets at least one of those seats, and then the rest of the seats are apportioned based on population count. Washington currently has nine seats in the House—six held by Democrats and three held by Republicans—but we've been growing fast enough over the last 10 years to likely merit another seat in time for the 2012 elections.

An additional seat would increase the state's clout in D.C. and could potentially shift the outcome of big national debates. This year alone, the House held close votes on everything from health-care reform (approved by only a nine-vote margin in March) to financial-industry regulation (which passed the House by 19 votes last December). Given that, it's easy to see why having a 10th representative from Washington State could be a big deal (and why the question of which party will end up controlling the new seat is an even bigger deal).

David Ammons, spokesman for the Washington Secretary of State Office, says state workers in Olympia are already preparing for the probable new district by crunching numbers and drawing maps—detailed down to the census block—of who lives where in Washington and how they've voted in past elections. It's clear, Ammons believes, that our new congressional district, if it indeed comes, will be located on the west side of the Cascade Mountains—where every district is currently held by a Democrat except for one, the 8th District, located on the east side of Lake Washington and represented by three-term Republican incumbent Dave Reichert.

"The pieces will come together somewhere in Puget Sound for the new district," Ammons says. "I don't see any way that it wouldn't be a Puget Sound district."

That's because, according to census projections, the two most overpopulated districts are Reichert's 8th and Southwest Washington's 3rd District, which is currently represented by retiring Democratic congressman Brian Baird. Under a scenario in which Washington gets a 10th congressional district, the 8th District would need to lose about 133,500 people in order to be equal in size to all other districts; the 3rd District, for its part, would need to lose about 114,500 people.

Look at the map on this page and it's not hard to imagine how one might grab chunks of the 8th and the 3rd, and then cobble those chunks together into a new district that encompasses liberal Olympia and conservative southern Pierce County. What's less clear is which way that new district might swing.

The scenarios are numerous and all politically combustible. Will so many rural conservatives be taken out of the 8th District that the state's most famous swing district ends up swinging right into Democratic hands? Will the 3rd District fall to Republicans if it loses lefty Olympia? And will the newly created 10th District tilt to the left or the right? At stake is control of not just one House seat, but several.

In the end, engineering this type of mystery is exactly the job of Washington's bipartisan redistricting commission, which is by all accounts the scrupulously fair antithesis of the kind of redistricting that happens in places like Illinois. The commission is designed to produce well-balanced districts that create unpredictable elections, in which every vote counts, while also meeting the approval of the even split of Republicans and Democrats who control the commission's votes (the legislature must then approve the maps).

It's worth understanding what's going on, says Washington State Democrats chair Dwight Pelz, because this largely ignored process has such a profound impact on whether votes in a particular district matter, or don't. "Redistricting," Pelz says, "is where 'one person, one vote' happens."