Obama, GOP presidential candidates file for Ill. ballot

January 7, 2012 9:09:54 AM PST
President Barack Obama and Republicans Newt Gingrich and Rick Santorum have all filed for a spot on the Illinois primary ballot.

They join Ron Paul, Rick Perry, Mitt Romney and others.

Submitting signatures on nominating petitions does not guarantee a spot on the ballot, and opponents can still challenge the paperwork.

The Illinois primary is March 20.