Polls show Romney and Rick Santorum in a tight race in Illinois.
But Romney strategists believe he will win thanks to support in the suburbs. Romney flexed his political muscle Sunday night with a town hall meeting in north suburban Vernon Hills Sunday night.
The candidate and his wife, Ann, arrived in Vernon Hills 80 minutes ahead of his scheduled Town Hall meeting.
The former Massachusetts Governor energetically broke the news of his landslide win in Puerto Rico to the delight of a standing-room-only crowd in the Sullivan Center Gymnasium.
"We stand for something, conservative principles that bring growth and good jobs and rising home values," Romney told the crowd. "That is why we are going to win.'
During his 35-minute appearance, Romney did not speak the names of his three primary opponents. Santorum, a distant second in the delegate race, stumped in Louisiana which holds its primary on Saturday.
But the former Pennsylvania Senator had help in Chicago, where Christian reality TV stars Jim Bob and Michelle Duggar -- famous for raising 19 children -- campaigned at the Moody Bible Church.
In Vernon Hills, the Romneys would not disappoint hundreds who could not get inside the gymnasium. They used a makeshift stage to address the overflow.
"We appreciate that you will be out voting, and we need you to vote multiple times. This is Chicago, right?" Romney said.
But during the scheduled program inside, it was one attack after another against President Obama.
"He said if he could not turn around the economy during his first three years in office, he would be looking at a one-term situation," Romney said. "We are here to collect."
Santorum, expected to be the principal competition in Illinois, did most of his campaigning Sunday in Louisiana, perhaps looking ahead.
He will resume his Illinois campaign Monday in Dixon. That is where Ronald Reagan lived as a boy and as a teenager.
Also noteworthy, Romney will also speak at the University of Chicago. Remember, that is where President Barack Obama once worked as a law professor.