By Kevin Frazzini

Anyone who thinks things are the same from one state to the next should consider redistricting.

It’s a fairly straightforward process in Iowa, for example, where a temporary advisory commission, not the Legislature, draws up the district lines, then presents its plan to lawmakers for an up-or-down vote. That’s a quickie description, of course, but Iowa’s approach works—for Iowa. The state, which has a relatively homogenous population of about 3.2 million, hasn’t faced a challenge to a redistricting plan since 1970.

It’s a different story in neighboring Illinois, home to nearly 13 million people and Chicago, one of the nation’s largest, most racially and economically diverse metropolitan areas. Lawmakers draw the lines in the Land of Lincoln, and since 2010 they’ve faced three attempts, including one this year, to wrest that power from them.

Just who should decide how districts are drawn was the topic of the session “Redistricting: A Distinctively Legislative Power,” at NCSL’s annual Legislative Summit on Monday.

Redistricting is the process of redrawing legislative and congressional district boundaries. The process occurs after every decennial U.S. Census and is based on numerous criteria, including population and geographical boundaries. It’s governed by the U.S. Constitution, the federal Voting Rights Act of 1965, as well as states’ constitutional and statutory provisions.

The core priorities in all states are to keep districts compact, contiguous and relatively equal in population. How states achieve those goals varies. In five states, a bipartisan or citizens’ commission draws the lines, and Iowa relies on its nonpartisan group of civil servants. Several states—Alaska, Delaware, Montana, North Dakota, South Dakota, Vermont and Wyoming—have just one congressional district and don’t worry about congressional redistricting. And in the remaining 37 states, the legislature decides where the lines will fall, though in some of them an advisory commission is involved in the process or takes over if the legislature can’t approve a plan.

“Approaches vary for different states, because pressures are different, especially in bigger states,” Tim Mapes, chief clerk of the Illinois House, said during the session.

Who should draw the lines? The answer depends on whom you ask. For more on the topic, visit NCSL’s redistricting webpages, and on the lighter side, check out the Redistricting Game.

Kevin Frazzini is the assistant editor of State Legislatures magazine.

Email Kevin