I fly this route about every six weeks, just got back last Wed. While there are dedicated check in desk for J pax (I assume this is what you mean by "obvious"?) there are no dedicated elite lines for security. You could encounter very lengthy queues. In addition, since you are checking in so close to flight time, you should be prepared for a pat down/thorough check of your carry on bags. Then there is passport control and then you catch the tram to the satellite terminal to get to the actual departure gate.

The bottom line: if your AA flight leaves at 11:00 am and you have not personally appeared to check in at the desk by 10:00 am you could lose your seat. This would be esp. true if you are flying J and there are other pax hoping to ugprade.

That gives you 55 minutes to make it from the city to the airport to the check in counter. Boarding usually begins at 10:20.

Your best bet is to hope the departure for ORD is delayed.