Ranger,

Chicago is much safer than it was before Obama became a (take your pick) community organizer or state legislator. Does the improved safety now versus then mean Obama solved the problem? Of course not. But similarly, that there are still problems does not mean they are Obama's fault (or that he was ineffective in dealing with them); it's far too much to lay on any one man's shoulders.

Beyond that, it would be impossible to hold the Olympics without greatly investing in Chicago, including improved safety. In that light, Obama (if he's able) getting the Olympics to Chicago does help to address safety issues in Chicago.

Your argument seems to be: there's violence in Chicago that Obama didn't fix, and he's trying to get the Olympics instead of fixing the problem. But really, Chicago has improved since Obama (so your first point rings hollow) and getting the Olympics will likely further improve the situation (so your second point seems to miss the mark as well).