Madeleine Doubek and Jay Young testified before the Senate Redistricting Committee on Wednesday during a meeting that featured partisan squabbling between Sen. Omar Aquino and Sen. Jason Barickman.

Illinois lawmakers formally kicked off a months-long redistricting process Thursday as a Senate committee received a primer on the basics of remapping, witnesses called for increased transparency and public involvement and lawmakers engaged in partisan squabbling over the type of data that will be used.

During a more than two-and-a-half hour meeting, Democrats on the Senate Redistricting Committee offered assurances to their Republican colleagues and several concerned witnesses that the remapping process, still in its early stages, would be transparent and ultimately lead to a “fair” map that reflects the diversity of Illinois.