Don't try to turn the rear hip!

You don't attempt to turn the rear hip behind you. You'll lose your support and negate the winding up of the torso. When you shift your weight to the rear (flexing/bending your forward knee and straightening your rear leg), your rear hip will naturally turn about 30 degrees. (Try it!) You then leave the right hip there and swing your left side anteriorly toward your right - maintaining what has become a long line extending from your spine down your rear leg - akin to a door hinge. Now you've rotated but have support from which you can initiate a powerful downswing.