Mitt Romney was characteristically vague in claiming to have paid at least 13 percent in taxes over the past ten years, saying “I did go back and look at my taxes and over the past 10 years I never paid less than 13 percent.”

Perhaps intentionally Romney did not identify the typical breakout of federal vs state income tax, property taxes, and sales tax that may have been included in the 13% tax rate he claims to have paid.

Given the multi-millionaire's significant real estate holdings and buying habits, it is not unlikely that property tax and sales tax made up a considerable portion of his overall tax rate.

State income tax may also have represented a portion of his claimed 13% tax rate -- leaving open the possibility that Romney paid zero in federal taxes some years, as has been suggested by Senate Majority Leader Harry Reid based on information from a former investor in Bain Capital -- where Romney served as CEO, Chairman and sole shareholder prior to "retroactively" resigning in 2002.