Reminder: Offshore Tax Havens Cost U.S. Government $100 Billion Per Year

On Tuesday, after Mitt Romney said he had "no idea where" his offshore investments were, Lindsey Graham (R-S.C.) came to his aid, saying "it's really American to avoid paying taxes, legally."

But by parking money in countries with tiny tax rates -- thus putting it beyond the reach of the American government -- wealthy businesses and individuals cost the federal government roughly $100 billion every year, according to a 2011 report from the California Public Interest Research Group. That's money that doesn't make it into the federal government's hands, even though it would probably come in useful -- again, given the trillion-dollar-plus national deficit.

As the CALPIRG report notes, many household-name corporations, including Goldman Sachs, General Electric, Exxon Mobil and Google, take advantage of offshore accounts, often saving billions in taxes in the process.

At the moment, of course, tax havens are more in the news because of people. (Although, remember: Corporations are people, my friend.) Barack Obama's campaign team has lately been giving Romney hell for the Republican candidate's use of offshore accounts in Switzerland, Bermuda and the Cayman Islands, and for his refusal to disclose more than a handful of details about his finances.