Spinning into Butter, Riverside Theatre's third production in its 21st season, is a sometimes-humorous look at very serious subjects: political correctness and racial politics in the new millennium. The work and the production have local roots. The play was written by Rebecca Gilman, who has an MFA from the University of Iowa and is an acquaintance of Ron Clark and Jody Hovland, co-artistic directors at Riverside. (Time magazine hailed Gilman as "an important new theatrical voice.") And director Bruce Levitt is a former University of Iowa faculty member and was director of the MFA. actor-training program at the school from 1977 to 1980.