Georgia legislators have returned to Atlanta this week for a chore they must handle only once or twice every decade: redistricting and reapportionment.

This is the process by which the boundaries of Georgia's legislative and congressional districts are redrawn so that each contains more or less the same number of people and reflects the population shifts recorded in the most recent census.

The majority of Georgia voters don't understand or pay attention to what goes on during the redistricting session, but the process is important because it will have a huge influence over the political outcomes of the next 10 years.

In Georgia as in most other states, redistricting is a process in which the party controlling the legislature (the Republicans in this state) maximizes their political strength at the expense of the minority party (currently the Democrats). The majority party can use redistricting to bolster its political standing over and above the preferences of individual voters.

Ten years ago, Democrats controlled the General Assembly and were trying to hang on to power in a state that was obviously trending Republican. They drew maps with weirdly shaped districts that packed as many Republicans as possible into as few districts as possible.

Georgia voters showed a preference for Republicans in the 2002 elections, as indicated by the results of the races at the top of the ballot. They elected Republican Sonny Perdue as governor with 51 percent of the vote and Saxby Chambliss as senator with nearly 53 percent
of the vote.

In the 2002 legislative races, where Democrats had stacked the odds in their favor through the redistricting maps they had drawn, Democrats won 30 of the 56 Senate seats and 108 of the 180 House seats. That's how the redistricting process becomes a powerful political tool.

Those Democratic maps were so egregiously drawn that a panel of federal court judges threw them out in 2004 and substituted politically neutral districts. Under those court-drawn maps, Republicans won a majority of the House and Senate seats in 2004.

In this redistricting round, Republicans control the legislature and are drawing the maps. Like the Democrats, they have the ability to use those maps to bolster their political power beyond the preferences of individual voters.

Georgia is a conservative and predominantly Republican state, but more than 40 percent of its voters still choose Democrats. In the 2008 presidential election, 47 percent of the state's voters cast their ballots for Democratic candidate Barack Obama. In the 2010 election, Democrats running for statewide constitutional offices were all soundly defeated, but they drew 42 or 43 percent of the vote in most of the races.

Redistricting maps that reflected the actual preferences of the state's voters as expressed in recent elections would leave you with a congressional delegation, a state Senate and a state House of Representatives that tilted roughly 60-40 in favor of Republicans.

When the Republicans finish their work in this special legislative session, they will have passed a congressional map in which 10 of the 14 U.S. House districts will have Republican majorities strong enough to elect a GOP candidate. Fewer than one-third of the congressional districts will be competitive for Democrats, and each of those districts will probably be won by an African-American candidate.

The redistricting plan for the state Senate could result in Republicans controlling more than two-thirds of the seats in the upper chamber, for a 38-18 advantage.

Similar results are expected under the map drawn for the state House. GOP consultant Mark Rountree estimated that 121 of the state House districts, which is more than two-thirds of the 180 seats, will be Republican-leaning districts. Democratic Party analysts contend that 123 of the seats will be in Republican-performing districts.

If you're a Republican, this is great news. If you're a Democrat, you probably are not very enthused about it.

In a state where nearly 60 percent of the voters cast their ballots for Republicans on election day, the majority party will be in a strong position to win nearly 70 percent of the seats in the General Assembly and more than 70 percent of the congressional seats.

That's how the redistricting process magnifies the power of the party that controls the legislature.

That is the magic of redistricting.

Tom Crawford is the editor of The Georgia Report, an internet news service that covers government and politics in Georgia.