Romney's refusal to measure up to his Father;s standard allows (and indirectly encourages) speculation and wild guesses of what he's hiding. Swill accounts? Sure. The Bahamas? Of course. Lots of fodder for speculation there.
But now we have a very logical reason - the desire to avoid government review of how fees were turned into fund investments. Wave that magic wand that the tax rate goes from 35% to 15%.
Now the New York Attorney General is investigating a dozen companies, including Bain Capital:
Inquiry on Tax Strategy Adds to Scrutiny of Finance Firms
The New York attorney general is investigating whether some of the nation’s biggest private equity firms have abused a tax strategy in order to slice hundreds of millions of dollars from their tax bills, according to executives with direct knowledge of the inquiry.
The attorney general, Eric T. Schneiderman, has in recent weeks subpoenaed more than a dozen firms seeking documents that would reveal whether they converted certain management fees collected from their investors into fund investments, which are taxed at a far lower rate than ordinary income.
The tax strategy — which is viewed as perfectly legal by some tax experts, aggressive by others and potentially illegal by some — came to light last month when hundreds of pages of Bain’s internal financial documents were made available online. The financial statements show that at least $1 billion in accumulated fees that otherwise would have been taxed as ordinary income for Bain executives had been converted into investments producing capital gains, which are subject to a federal tax of 15 percent, versus a top rate of 35 percent for ordinary income. That means the Bain partners saved more than $200 million in federal income taxes and more than $20 million in Medicare taxes.
It's important to note that the investigation is said cover a period of time after Romney "retired", but it should be noted that Romney continues to receive money from Bain and he is not totally excluded from having "benefitted" from the shell game.
Finally, I doubt if Romney wants 12 years of returns made public for those who are investigating this shell game. or reviewed by experts (who happen to be Democrats) to see just how much Romney avoided in taxes by playing this game. Romney probably has a good reason to keep those returned hidden from the experts and the public.