Illinois Attorney General Lisa Madigan (D) will run for re-election to her current post in 2010, according to a Democratic source aware of the decision, ending months of speculation about whether she might make the leap to a Senate or gubernatorial bid.
Like everyone else, I'm a little surprised, since polling indicated that Madigan would win either race handily and could basically have her pick of which promotion she wanted. Her rationale, though, I would guess, is that she has always had her heart set on Governor and becoming a Senator would be a distraction toward that end... and with new Governor Pat Quinn having quickly become fairly popular and solidified his status, she may feel she's young enough to not have to roll the dice by rushing into primarying him out (and maybe she'd rather wait until the economy improves and being Governor is a less onerous job).
While this makes the 2010 Governor's race pretty boring -- Pat Quinn likely to romp over a second-string state Senator to be named later -- this now makes the Senate race very interesting, as Rep. Mark Kirk may be much likelier to get in (giving the GOP a competitive figure, but also opening up IL-10 for us), and it may also attract more Dems to the crowded field (currently including Treasurer Alexi Giannoulias, Kennedy Chris Kennedy, Chicago Urban League President Cheryle Jackson, and possibly incumbent placeholder Roland Burris). (H/t fitchfan28.)