At least 20 members of the Illinois General Assembly will not seek re-election in 2012, according to the Associated Press. That figure bumps up to 24 when compared to four years ago, when those who retired prior to the 2010 elections are considered. Ten state Senators are retiring, five from each major political party. Ten members of the Illinois House will also step away from their posts; seven being Democrats and three coming from the Republican party.

Experts say the legislative remap is part of the reason for the turnover.

“I suspect that this is probably higher than 10 years ago because of the combination of things,” Kent Redfield, emeritus professor of political science at the University of Illinois Springfield, told the State Journal-Register. “The legislature is more centralized than it used to be. This is a particularly difficult map for the Senate Republicans.”

The Chicago Tribune reported on Friday that the legal battle over the remap could force filing dates to be pushed back. The filing schedule is currently set to run from November 28 to December 5.