Republican Aaron Schock and Democrat Colleen Callahan will have at least one more opponent in the race for the 18th District Congressional seat.  Green Party Candidate Sheldon Schafer officially threw his hat into the ring by filing this week with the state Board of Elections.  The Green Party is mostly known for Rich Whitney's run for Illinois Governor in 2006.  Whitney received 10 percent of the total vote in losing to Governor Rod Blagojevich.  Schafer says the philosophy of the Green Party is grassroots democracy with slow and steady growth. The Party goal is to fill two-thirds of ballot positions across the state in the November general election.  Schafer says the general reaction in his choice to run has been mixed early on.  However, Schafer says interest in the Green Party is increasing.  He says his political group is in the election process for the long haul.