There’s always a political balancing act to disclosure. On the one hand, when a politician withholds information, it raises suspicions and triggers attacks that he or she isn’t being transparent. But on the other hand, a candidate doesn’t want to release potentially damaging information. In his 2008 presidential run and up until this point of the current race, Mitt Romney obviously made the calculation to err on the side of not releasing his the tax returns. But this week, the factors contributing to that calculation have changed dramatically.

During Monday’s debate, Romney struggled to explain his decision not to release his returns, eventually saying he would “probably” do so in April. Then, the next morning, he said his effective tax rate was around 15 percent, giving opponents a line of attack. Tonight, ABC News reports that Romney has “millions of dollars of his personal wealth in investment funds set up in the Cayman Islands, a notorious Caribbean tax haven.”