Alonzo Spellman syndrome - predicate future performance on the guy's most recent couple of games. Tracy Porter has a full NFL resume. An eight year career spread over five teams, and a history of missing games for injury. Generally speaking, a one INT/yr guy. Signed by the Bears at the league minimum for one year, meaning no one else in the NFL thought a whole lot of his previous body of work. He'll be 30 next year, a point where even durable CBs start to break down (see Tillman...). And people think the Bears should be jumping to throw a multi-year, guaranteed, high-level contract at him? Seriously?
Look, I hope the Bears can work something out with Porter to keep him around for another year or two. But if another NFL team wants to throw a lot of guaranteed money at him, fine. Let him go and go find the next stopgap CB, while rebuilding the talent base through the draft. Rebuilding around 30yr old veterans with very average careers is silly. I doubt Pace would fall into that...