Oz is hardly a "liberal Republican." The guy seems to have no real ideological beliefs whatsoever, and any he's had he's willing to flip-flop on (kind of like Romney). His only real beliefs seem to be based on grifting and opportunism.
So from that it sounds like the comparison should be apt, but I would agree with this:
One big difference: Romney has actually won multiple, statewide elections over the course of his political career, something it seems increasingly unlikely Oz will do.
On top of that Romney does actually have appeal to at least some demographics in the country, Mormons specifically, but Oz doesn't seem to appeal to anyone.
