Legislative and congressional redistricting can cause some of the toughest political fights any state can have.

The temptation to control for partisan advantage when and how the lines are redrawn has led in some states to outrageous gerrymandering, where representatives of “safe” seats control the debate from partisan extremes.

Fortunately, under Maine law we have a much better system in which a nonpartisan panel studies population shifts to produce the fairest district lines.

The commission’s recommendations have to be approved by a two-thirds majority, practically guaranteeing that neither party can run roughshod over the other.

But as we learned this summer, Maine law may not be good enough. A narrow partisan majority can change the law requiring a two-thirds vote and then pass the redistricting as if the requirement didn’t exist. That didn’t happen, but the threat of such a move hung over the redistricting debate and could have derailed a consensus.

That’s why voters should say “yes” to Question 4, which would give the statutory redistricting process the protection of the state constitution.

Partisan lawmakers would not be able to threaten to change the law and redraw districts to suit their political interests because such a move would be impossible. Passing this amendment would mean that redistricting would be done every 10 years, beginning in 2013, and would follow the process that is now defined in state law.

Maine should not aspire to repeat the outrageous acts performed by other state legislatures. We have a good system that treats all parties fairly and it should become part of the constitution.

We urge you to vote “yes” on Question 4.