The Chicago Bears must face a First Amendment claim brought by a man who alleges he was turned away from a pregame event at Soldier Field because he was wearing Green Bay Packers clothing.In a written opinion last week, U.S. District Judge Joan B. Gottschall did not rule on the merits of Russell Beckman’s contention that the Bears’ dress code violates his right to free speech.But Gottschall held Beckman had presented enough evidence to pursue his challenge to a policy that bars those participating in pregame …