They’re only lines on a map, but because they define political boundaries and the way the state runs its government, they’re not to be drawn without careful thought and oversight.

The state Reapportionment Commission meets today — it convened for the first time earlier this month — to organize and begin to translate the new 2010 Census data into sensible voting maps.

The last commission in 2001 accomplished a major improvement by eliminating the most senseless of the "canoe districts," such as those in the state House and Senate that lumped some Puna neighborhoods on the Big Island in with East Maui. There are still a few unavoidable exceptions — Lanai being tagged to Maui, for example — but the current commission should maintain single-island districts as much as possible.

Growth in Hawaii was not enough to change our congressional count of two representatives — the total population is now 1.3 million. Hawaii would need close to 2 million residents to gain a new U.S. House seat. There’s been a clear westward shift of Oahu’s population center and some expansion on the neighbor islands, both factors that will move the U.S. House district line.

But the principal challenge will be the redrawing of the state legislative boundaries in ways that ensure that most residents are represented by people who have close ties to their communities. It’s not as easy as it sounds, because that goal has to be balanced against another: making sure each elected lawmaker represents more or less the same number of voters as the other legislators in his or her Capitol chamber.

The math here can be tricky. In 2001 there was a dispute over whether to count nonresident military dependents who are posted in Hawaii in each district population. Ultimately, after a lawsuit threat, the old commission made the right choice and excluded them as well as another transient cohort: college students living away from the district. The state Constitution dictates that only "permanent residents" are counted, so it’s hard to see how these two groups qualify.

The state Office of Elections has posted an informative "guide to redistricting" on its website (hawaii.gov/elections/reapportionment/) that explains the principles. Ideally, districts should be compact, both geometrically and geographically. They should be contiguous (the remaining canoe districts are the notable exceptions). And they should preserve socio-economic communities as much as possible. The commission should see that the electoral clout of communities isn’t "submerged" by dividing them among two or more districts.

And the community needs to watch to make sure the commission is adhering to these principles as much as it can. The commission is on a 150-day deadline; the proposed plan is due on Day 100, with the remaining time devoted to public comments.

The panel is bipartisan and comprises eight appointees named by legislative leadership on both sides of the aisle. The Democratic majority tapped Lorrie Lee Stone, Anthony Takitani, Clarice Y. Hashimoto and Harold S. Masumoto; GOP members are Calvert Chipchase IV, Elizabeth Moore, Dylan Nonaka and Terry E. Thomason.

All of this may sound like dull, plodding work to the average voter. But politicians pay close attention because new lines could separate them from their electoral strongholds. So redistricting matters to voters — it will affect whose names appear on their ballots. Voters should hold the commission accountable for producing an election plan that’s both rational and fair.