Makes you wonder what Mitt is hiding in those tax records don't it? Why won't Romney release more tax returns?

So, what are the issues?

The first is Romney's Swiss bank account. Most presidential candidates don't think it appropriate to bet that the U.S. dollar will lose value by speculating in Swiss Francs, which is basically the rationale offered by the trustee of Romney's "blind" trust for opening this account. What's more, if you really want just to speculate on foreign currencies, you don't need a Swiss bank account to do so.

The Swiss bank account raises tax compliance questions, too.

The account seems to have been closed early in 2010, but was the income in fact reported on earlier tax returns? Did the Romneys timely file the required disclosure forms to the Treasury Department (so-called FBAR reports)?

The IRS announced in 2009 a partial tax amnesty for unreported foreign bank accounts, in light of the Justice Department's criminal investigations involving several Swiss banks. To date, some 34,500 Americans have taken advantage of such amnesty programs. Did the Romneys avail themselves of any of these amnesty programs? One hopes that such a suggestion is preposterous, but that is what disclosure is for -- to replace speculation with truth-telling to the American people.

Second, Romney's $100 million IRA is remarkable in its size. Even under the most generous assumptions, Romney would have been restricted to annual contributions of $30,000 while he worked at Bain. How does this grow to $100 million?

One possibility is that a truly mighty oak sprang up virtually overnight from relatively tiny annual acorns because of the unprecedented prescience of every one of Romney's investment choices.

Another, which on its face is quite plausible, is that Romney stuffed far more into his retirement plans each year than the maximum allowed by law by claiming that the stock of the Bain company deals that the retirement plan acquired had only a nominal value. He presumably would have done so by relying on a special IRS "safe harbor" rule relating to the taxation of a service partner's receipt of such interests, but that rule emphatically does not apply to an interest when sold to a retirement plan, which is supposed to be measured by its true fair market value.

Third, the vast amounts in Romney's family trusts raise a parallel question: Did Romney report and pay gift tax on the funding of these trusts or did he claim similarly unreasonable valuations, which likewise would have exposed him to serious penalties if all the facts were known?Fourth, the complexity of Romney's one publicly released tax return, with all its foreign accounts, trusts, corporations and partnerships, leaves even experts (including us) scratching their heads. Disclosure of multiple years' tax returns is part of the answer here, but in this case it isn't sufficient. Romney's financial affairs are so arcane, so opaque and so tied up in his continuing income from Bain Capital that more is needed, including an explanation of the $100 million IRA.

Finally, there's the puzzle of the Romneys' extraordinarily low effective tax rate.