While you _could_ achieve this with a very thick support structure, that's really inefficient (wasting time and filament) and is so dense that it is hard to remove. (Yeah, I tried, it worked, but took forever to print and wasted a ton of filament).
One thing to keep in mind is that the supported object might be an irregular shape, so I think that a simple raft wouldn't work.
What you really want is a thin support structure (e.g. 10%) until you get near the top, then a dense support (e.g. 50%) structure for a few layers (each rotated 90 degrees from the previous layers), then a gap, then the bottom of the object. That way the loose support holds up a denser mesh, which then holds up the object. And it would fit irregularly shaped objects.