INDIANAPOLIS (AP) _ Purdue University alumni are calling for Mitch Daniels' removal as president following the publication of emails showing he tried to silence critics in higher education and “disqualify the propaganda'' at Indiana's teaching colleges while governor.
 
  Society for an Open and Accountable Purdue spokesman Aaron Hoover said Wednesday that Daniels' emails are grounds for removal. Hoover and other alumni protested Daniels' selection for president last year by a board of trustees he appointed.
 
  Daniels denies he ever attempted to limit speech at Indiana universities. But emails obtained by The Associated Press show he sought a “cleanup'' of courses at the state's teaching colleges in 2010 as part of a quest to keep liberal historian Howard Zinn out of Indiana classrooms.