Politicians are circling around hedge funds like vultures. They want to raise taxes on hedge funds, maybe by treating their capital gains as normal income. Why? Because hedge funds are mysterious — do you know what they really do? — and they have a lot of money. Make billion-dollar profits, get headlines, attract taxers — it's as certain as ants at a picnic.
There are whole books on the correct theory of taxation. I've always assumed that Democratic members of Congress operate on the theory most clearly enunciated in 1990 by Sen. Barbara Mikulski (D, Md.):
Let's go and get it from those who've got it.
There are many theories of taxation, such as Haig-Simons, the Tiebout model, and the Ramsay Principle. But I'd bet that the Mikulski Principle explains actual taxation best.