No matter how Jack Lew performs at his Senate confirmation hearing on Wednesday, his nomination to be Treasury Secretary has already produced one big winner: the Cayman Islands. The Caribbean low-tax haven is getting a political rehabilitation thanks to Mr. Lew's participation in a Cayman-based fund he invested in while working at Citigroup from 2006-2008.

For years Democrats have denounced the Caymans, which has no corporate income tax, as a refuge for tax cheats. In 2012 President Obama ripped Mitt Romney for investments based there. But now an Obama spokesman suggests that Mr. Lew's Caymans investment, a Citigroup fund he chose to invest in, was a model of transparency and says that "Jack Lew paid all of his taxes and reported all of the income, gains and losses from the investment on his tax returns."