Trotter was arrested at O'Hare International Airport on December 5 after TSA agents allegedly found bullets and a gun during the screening process. His attorneys had hoped the charge would be thrown out during Wednesday's court appearance.
"I was hoping to have a preliminary hearing and yes, I was hoping for a dismissal. I think there would have been a finding of no probable cause," Thomas Durkin, Trotter's attorney, said.
Instead, the judge granted a prosecution request to let the grand jury hear evidence in the case. At issue: if Trotter knowingly had the unloaded pistol and ammunition in his carry-on bag.
"It's a question of knowledge. It's not intent, it's knowledge and the state has the burden of proving knowledge," Durkin said.
Trotter is running for Congress, hoping to replace Jesse Jackson Junior, who resigned in November, in the 2nd Congressional District. Now, he'll campaign while facing a felony.
Before the arrest, Trotter was considered a frontrunner for the endorsement of Democratic party leaders.
He appears in court next on January 17, 2013.
"Certainly I would like to have the support of the democratic slating committee on Saturday," Trotter said.
"Senator Trotter has been stalwart in terms of bringing services, delivering stuff for our community," Ald. Michelle Harris, Democratic Committee member, said.
Other committee members say the gun arrest is having a negative impact:
"You can't pretend like it doesn't exist. So, it's just one of many factors that will be considered," Ald. Leslie Hairston, Democratic Committee member, said.
Southside Alderman Anthony Beale-- who is also running to replace Jackson--says a Trotter endorsement would further tarnish Chicago Democrats' reputation.
"I think it would be a cloud put over this race if something like that was to happen," Ald. Beale said.
Trotter's lawyer said if his client were not an elected official, the state's attorney's office would not have field the charge. The state senator still believes his 24 years in office will have a bigger impact on the campaign for congress.
"I believe that my credentials and my work in that community certainly makes me highly qualified for that position," State Sen. Donne Trotter said.