SPRINGFIELD — Two 5th District Appellate Justices — Republican David K. Overstreet and Democrat Judy L. Cates — will face off later this year to fill the downstate seat on the Illinois Supreme Court currently held by Justice Lloyd A. Karmeier.Cates ran unopposed in the primary, locking-down the Democratic nomination.Overstreet secured a decisive victory over 5th District Appellate Justice John B. Barberis Jr., earning 76.5% of the vote, according to unofficial election results. Barberis obtained 23.5% of …