This race has already attracted a lot of national attention from both parties, which are pouring money into the campaigns.
The incumbent Congressman Walsh attracted national attention from doctors' groups and Planned Parenthood with his comments Thursday night on abortion.
With opponents protesting outside, Congressman Joe Walsh said he wanted to clarify his comments on abortion made during and after a televised debate.
Those comments are getting national media coverage after Walsh said he opposes abortion under any circumstances, and that abortion is almost never necessary to save the mother's life.
"With the advances in modern medicine, an invasive and traumatic procedure like an abortion is often, thankfully, not necessary to save the life of a mother," he said.
Many obstetricians however say that's simply not true, that while there are fewer cases these days than in years past, there are a number of conditions some pregnant women develop that become life threatening.
"We probably handle one or two cases every other month," said obstetrician Dr. Xavier Pombar.
The congressman says the issue is personal with him, but it has created a political firestorm. Walsh and Democrat Tammy Duckworth, who is pro-choice, both hope to appeal to women voters.
"It's really sad he would take this position infringing his rights on a woman's right to choose and her decisions within her how body and within her own faith," Duckworth said.
Some observers liken Walsh's position to the comments by embattled Missouri senate candidate Todd Akin, who said women could not become pregnant from a forcible rape.
"A lot of people think his remarks are pretty extreme and perhaps not well-informed, and that may backfire on him," ABC7 political analyst Laura Washington said.
Congressman Walsh clearly softened his comments from Thursday night when he said abortion is never necessary to save a woman's life.
He allowed Friday that there are some instances.
It remains to be seen how it will affect this extremely tight race.