For reasons of union solidarity, Lansing Michigan police don't show up to help Michigan State Police with unruly pro-union demonstrators. Lansing had an agreement to step up and help, but union bosses don't want any arrests made so they pulled the support of Lansing Police creating a dangerous situation for the Michigan State Police. Unions do not care about anything but increasing wages and benefits for union workers, so the union bosses can increase union dues whenever they like.
source: http://michellemalkin.com/2011/03/18/state-police/