All the studies I've seen say it doesn't actually save us anything. It's a huge pain for some of our best industries, and no one likes losing yet another hour of daylight in the fall evenings.
So, who is the giant deep pockets supporter of DST with enough pull to not only have congress keep it around, but keep monkeying with the date? I'd believe it if we enacted it years ago as an attempt to save energy and were just stuck with it ever since if the congress just never got around to getting rid of it. But they constantly fiddle with it. They don't fiddle with anything unless someone with deep pockets tells them to, so who cares that much about it to actually keep it from dying?