Trying to knock out the defamation and false-light complaint that John Garrido filed after losing the 2011 election for alderman in Chicago’s 45th Ward, the principal defendants — the winning candidate, John Arena; his campaign committee; and three unions that supported Arena — invoked the Illinois Citizen Participation Act, which provides protection against “strategic lawsuits against public participation.” Garrido contends the defendants defamed him and painted him in a false light …