CHICAGO (AP) -- Illinois Attorney General Lisa Madigan has decided to run for re-election instead of seeking higher office.

That's according to Madigan's political director, Mary Morrissey. Madigan plans a news conference this afternoon to discuss her plans.

The Democrat's decision dramatically changes the landscape of the races for governor and Senate in Illinois, which has seen both offices rocked by scandal.

The well-connected daughter of powerful Illinois House Speaker Michael Madigan had been seen as a frontrunner for either seat. She'd been encouraged by Democratic leaders all the way up to the White House.

Her announcement is likely to set off a domino effect, as candidates from both parties were waiting for her decision before jumping into races for statewide office in 2010.