They have not backed out of it, just want more time to twist the arms of Dems in the senate to approve it. Right now Senate Dems know better, but Obama knows that if he does not get ratification before the election he never will.
Bookie look it up. Several Dem Senators sent a letter to Obama a few days ago saying that would not support the treaty. Without them there is no chance of getting it ratified even though Obama has said he wants it.