Connecting at JFK this Spring?

Q. When I booked a flight from San Juan to St Louis a few months ago, we were to have a layover at JFK of about 2 1/2 hours. Since then, we've been informed by our airline that the departure time of our flight from San Juan has been changed. In fact, it's changed several times. Do we have any right to expect the airline to switch us to a better flight to ensure we make our connection?  As it stands,  there is currently a one hour layover at JFK. I'm not sure that will be enough time to make our flight, and in the past we've had horrible luck departing SJU on time, no matter which airline we fly. I fear if we miss our connection, we might be told there are no more flights to St Louis that night, that they cannot ticket us on another carrier, and then being told we shouldn't have booked a flight with such a small window to connect! Guess I'd like to be armed with every piece of knowledge I can get ahead of time.

A. You should certainly ask for a longer layover, and without having to pay a change fee. If you don't like the answer you get, try again and then again. One thing to consider here is that JFK will be closing its longest runway for 120 days, from about March 1. This runway handles about 30% of JFK's traffic, so there will probably be some delays, and this may be one reason why your flight has been rescheduled so many times.