Are you using AA847 out of MCI? That gives a normally very comfortable 90 or so minute connection at DFW. The thing to do here is that if the delay is obvious whilst you are at MCI, get the staff there (not at DFW) to re-route you via Chicago - which would be my preference anyway. That way you can get on to BA1547 (and there are other options that way too). Once you're on that MCI-DFW aircraft you're stuffed.

My experience is that if the delay is heavy and weather related, AA will probably be disinclined to be too helpful. If it is mechanical and the desk is not overwhelmed and you get a good gate agent, they can and will move Heaven and earth for you.

Incidentally I hope you will make the flight, I wouldn't worry too much about hypotheticals, but always good to know your Plan B.