Do we call, push or fold. I would fold with the reasoning as follows:

Call:
If you put him on a middle pair he is a slightly ahead of you. He has about a 57% chance to win the hand. Now given what is already in the pot, calling this has a very slight positive EV if you are absolutely sure he has a lower pocket pair. However, I don't think you can rule out him holding AA or KK. If this is even a slight chance it makes calling the bet -EV. Even if we rule out AA or KK as a possibility, I would not call the bet even thought it is slightly +EV, since the high variance does not make the tiny +ev worth it.

Push:
So I would not call, but pushing is another possibility. If we push, the relatively small raise that we already put in the pot could become insignificant (it depends on the depth of our stack compared to the first raise) and make the move –ev, if we knew we would be called. This is somewhat offset by the chance the he may fold to an all-in re-raise. If you believe there is a small chance he holds AA or KK, the push becomes -ev. In the end, I would not push here. Any possible +ev is too small for me in comparison to the variance of the move.

However, as Dalecooper said, he pushed, not for the value on this hand, but to send a message for future hands that he could not be run over. The value of that greatly depends on your playing style.