Mayor Rahm Emanuel immediately faced stiff resistance Wednesday to a key pillar of the proposal he’s hoping will cement his status as the guy who responsibly took on Chicago’s crushing public pension debt. Emanuel delivered a City Hall speech calling for a state constitutional amendment to allow a reduction in public workers’ pension benefits, an idea several high-profile candidates to follow him in office ripped and new Democratic Gov.-elect J.B. Pritzker dismissed as a non-starter. Emanuel treated his pension blueprint with pomp and circumstance, delivering it to aldermen in a half-hour speech big on legacy building at the start of the City Council meeting.