Gerrymandering is a form of boundary delimitation (redistricting) in which electoral district or constituency boundaries are deliberately modified for electoral purposes, thereby producing a contorted or unusual shape. The resulting district is known as a gerrymander; however, that noun can also refer to the process.
In Illinois, there are two ways to rearrange the district map. The first is through a legislative bill. Such a bill would require a majority of the votes out of both chambers. Then, it would need to survive a Governor's veto. So far however, each of the three years 1980, 1990, and 2000, the legislature have been Democrat and the Governor has been Republican. As such, the Democrats' map has never survived the Republicans veto.
The next step is a committee of eight, four Republicans and four Democrats. This committee is chosen by the leadership or Michael Madigan, John Cullerton and Tom Cross. Of this committee, five of the eight need to agree on a map. In reality, this means a legislative game of chicken that ends in a deadlock each and everytime. Both sides draw the map to benefit their party. No one wants to cross over because they'd then be signing on to a map that hurts their party. As such, this committee has never once received the votes necessary.
Then, we move to the third possibility. In this case, a Republican and a Democratic envelope is placed into a hat. One of the two envelopes is picked and whichever party is chosen gets to have their map drawn. That's what's happened each of the three times. It's the most cynical and least Democratic way of choosing a district map. On top of all this, there's an unwritten rule that no matter who draws the map, all four leader's district stay as safe as possible.
The Putback amendment attempts to control the process of Gerrymandering as much as possible. First, anyone is now allowed to submit a map. Each map will be judged on a series of categories including comptetitiveness, compactness, etc. Each category will be quantified. The legislature will again choose a panel of 8, four Democrats and four Republicans. It will be up to this commission to come up with a way to quantify each category. Then, each submitted map will receive a score. Of those three, the legislature, based on a three fifths vote, will choose one. If one isn't chosen then the map with the highest score will win by default. Finally, the Constitutionality of each map and of the process itself (like if the commission chose an unconstitutional way of quantifying) can be challenged by anyone, and not just the AG.
Here is part one and part two of this series.