"The funny thing is we came here because we knew the debate would be on," said Jamie Shuttleworth.
Undecided voters are hoping to hear something that sways them.
At the Chicago History Museum, Senator Obama saying the best way to save money is to get out of Iraq drew the biggest reaction.
"I was displeased actually to see they didn't have specifics of what this is going to cost us," said voter Irene Reed.
"I'm seeing and hearing experience from McCain that I'm not seeing from Obama at the present moment," said Jason Kmet.
In Evanston, Northwestern University journalism students are watching the candidate's with a critical eye.
" I think Obama is good at giving well-prepared speeches but is not as strong on his feet whereas I feel that McCain is better on his feet," said Aaron Michnowski.
"Being 19, this is my first presidential election and it really helps formulate some of your opinions, like who you want to vote for," said Reynaldo Sanchez.
Not far from Obama's Hyde Park home, a decidedly partisan party, where plenty are ready to heap praise on the performance of their neighbor.
"We are excited to be here, strong supporters of Obama. We live on the Southwest Side of Chicago and traveled here to his home community to come and support the cause," said Denitra Griffin.
An estimated audience of more than 80 million people tuned in to see how the two candidates performed.