It's a reversible pump. If one direction is working, then the pump should be fine. This is most commonly a bad solenoid. If one is bad, then replace them both, because the other isn't far behind.
A temporary method to hopefully get you out of a jam is to hit the button in the direction that isn't working as many times as fast as you possibly can. The switch collapses a gate in the solenoid that closes the circuit. You should hear it 'click'. slam it closed in succession and you can usually knock enough corrosion off to get it to work (enough to get home).
Another work-around and test is to take a screwdriver (I prefer an insulated handle) and bridge the gap across the posts on the solenoid. This effectively 'jumps' the solenoid by bypassing the internal gate and closing the circuit externally. This will both get you out of a jam and verify it is actually the solenoid that is bad.
Remove one from the pump bracket and buy two. Then replace them both.