your first flight is delayed. Then you are screwed.

It also helps to be towards the front of the plane on your first flight, so you don't have to wait until the whole plane is empty before you can get off.

And it helps to be familiar with the layout of the airport. You will definitely have to take the train, but as long as you are paying attention, that's easy. Just don't go past the escalator down to the train in your hurry, and don't go down the wrong side (which are both fixable errors, but they would add an extra delay).

You might have to do some jogging, and you probably won't be at the second gate when boarding starts, but as long as you move right along, you ought to make it before they close the door. Delta knows how far you have to go to make the connection, and they want you to make your flight. So that works in your favor.

Wait--will you have little children in tow? If yes, then I would not want to try to make that tight of a connection.