[5][6] Quinn defeated Hynes by just under 9,000 votes, while Cohen won an upset over establishment candidates by just over 3% campaigning as a political outsider.

[11] Scott Lee Cohen was replaced as the Democratic lieutenant gubernatorial nominee by former Carbondale City Councilwoman Sheila Simon after he withdrew due to allegations of abuse toward his wife and other charges.

Cohen was criticized for his having been charged with domestic battery, in which he was accused of holding a knife to the throat of an ex-girlfriend who was also a convicted prostitute.

[19] On March 27, 2010, the Democratic State Central Committee chose a replacement candidate, Sheila Simon.

[26][27] Dan Hynes, who placed second in the gubernatorial primary, denied interest in replacing Cohen on the ticket.

[27] Jeff Melvin, a 21-year retired army veteran, also applied to the open nominating call for the Democratic lieutenant governor position.

[28] At one point during the campaign, Quinn, struggling to make up ground amidst poor polling numbers against Brady, accused his Republican opponent of supporting a bill to kill puppies.

Quinn initially had a large lead when results first began to come in, as heavily populated areas tend to report their votes faster.