They may share the same name and some of the same genes, but Pat Ulen, left, and Adele Rich don't share their sons' politics. The mothers and sons faced off as students and teachers last week in an Elderhostel class, "Contemporary Issues Facing Our Nation," taught by Robert Rich, director of the Institute of Government and Public Affairs; Tom Ulen, professor of law; and Paul Quirk, professor of political science. Class discussions - and perhaps family dinner-table conversations - were livelier since Rich's mother is more conservative than he; Ulen's more liberal. Elderhostel programs - on topics such as Leonardo da Vinci, Shakespearean theater, jazz dance, the Middle East and the media - continue through July on campus. Other summer programs include the long-standing Russian and East European Summer Research Laboratory and Illinois Summer Youth Music, as well as the Illinois Minority Science Internship Program, Young Scholars in Agriculture Program, Summer Aviation Workshop, Teaching China in the Pre-Collegiate Classroom course, Illinois Software Summer School and sports camps for athletes of all descriptions.