[5] Mulligan first ran for the Illinois House of Representatives in 1990, eventually losing the Republican primary to conservative incumbent Penny Pullen by six votes.
The case, Pullen v. Mulligan, was later cited by Vice President Al Gore's legal team as precedent for counting "dimpled chads" during the 2000 Florida recount.
She was recognized for her expertise in prescription drugs, problem and compulsive gambling, health insurance coverage and reforms, welfare to work and victims' rights.
She served as majority chair or minority spokesman of the Illinois House Human Services Appropriations Committee for 10 years.
Following redistricting, Mulligan opted to seek election in the 55th District, but failed to make the ballot after collecting below the minimum threshold required number of voter signatures.