The Rev. Jesse Jackson vowed to force a confrontation after school officials in Decatur, Illinois, refused to reconsider the expulsions of six students involved in a brawl at a football game. At a church rally that drew about 400 people last night, nearly everyone, including the students involved, stood when Jackson asked who was willing to be arrested at Eisenhower High School. Jackson threatened to cross police lines today if the school board doesn’t agree to let the students return to regular school in January, providing they maintain good grades and behavior in alternative school.