I can understand why Mayor Daley stiffed former 20th Ward alderman Arenda Troutman at yesterday’s ceremony for the new Kennedy-King campus in Englewood.

After her indictment last year, she turned into one of his more vocal critics in the council, even voting against the Olympics.

But Shirley Coleman? The mayor’s people didn’t invite her to yesterday’s ceremony either, and she was one of Daley’s most loyal council supporters. She provided one of the three flip-flop votes he needed to kill the big-box living-wage ordinance, and it probably cost her last April’s election to Joann Thompson, who was backed by the unions.

Although, come to think of it, Coleman also voted against the Olympics, a desperate, last-ditch move to stave off defeat by showing she wasn’t a complete Daley puppet.  Maybe that’s why the mayor snubbed her at yesterday’s ceremony. He has a very long memory.

Any way you look at it, this should be a lesson for other loyalists thinking about the mayor’s TIFs, taxes, and Olympics. Vote against him, even once, and you’re exiled.