I was born and raised in Chicagoland (that basically means the greater Chicago area including suburbs) all my life. I lived in Milwaukee for a period of time and have traveled most major cities in my life. I have a strong love/hate relationship with our fair city...And I'm torn about the Olympics.
All of this will be moot soon enough since the voting for the 2016 bid will be over soon, unless, of course, there is a tie...
Even the suburbs will be cluttered with traffic - Chicago is big...But the Olympics are HUGE. To offset having the entire downtown area bursting with people and traffic, they will be having the suburbs host some events...And that's not even considering people staying in hotels. Traffic is bad enough on a day-to-day basis, we don't need something like this jamming us up...We might as well walk to our destinations...Or maybe buy a Segway?
Money - I'm not sure how many people are aware of Chicago's (Cook County's) sales tax...but it's enormous at 10.25%. I could be mistaken, but I think it's the highest in the whole US. We also have to endure things like parking meter hikes, and even cab drivers have raise their prices and added on surcharges. While most of the games are funded by corporations like Coca Cola, not all of it is.
Back to that money... - The city's limited funds could probably be better spent on public schooling. There are frequent school violence cases, too many dropouts, and just negativity all around in many public schools here. This should be a top priority.
Crime - I'm not talking about Chicago's typical reputation for white collar crime either...People will always take advantage of situations like this, and even small things like cab drivers adding illegal surcharges would be a very likely scenario. Pickpockets and other possibly violent crimes are not going to just disappear. Note that this is a bigger issue in Rio...
Jobs - It's estimated that more than 100,000 jobs would instantly open up if we win the bid. That's a great thing, even if only temporary, it's still 7 years away. There would likely be residual jobs for clean-up, crowd control, etc.
Money - This is also a pro since the city would see TONS of tourism dollars, but the cons of this are still in effect. Assuming sponsors do pick up most of the tab for building and organizing, the city shouldn't have to exert itself too much financially.
Infrastructure - We have major professional sports teams...We have lots of venues and space to host sporting events. Even without leaving the city limits, Soldier Field and the United Center are massive. Leaving the city, there are dozens of college campuses and sports-type places. This is definitely something we have over our competition.
US of A - This is a bid for Chicago directly, but all of the US. There is no better city in the US right now to host this (I realize I may be biased there...) and we haven't hosted the Games since '96 in Atlanta. Madrid just had it in Barcelona and Japan with Nagano. South America will have its time to shine, but I think having Obama talk directly to the voting committee, we're solid.
I probably wouldn't go to any of the events assuming we get the Olympics, but I think I'd like to have them here. I, of course, will likely compalin about all the traffic, but I do that anyway.