WASHINGTON — The American Association of University Professors voted Saturday to censure the University of Illinois at Urbana-Champaign and three other institutions, while protesting planned changes — pushed by Republican lawmakers — to tenure and shared governance within the University of Wisconsin System. Members also discussed at their annual meeting here how the association might better respond to administrative moves to close troubled colleges in light of the shocking Sweet Briar College announcement earlier this year. They called that decision the first of many coming threats to similar institutions in financially and politically turbulent times.