I can describe Mitt Romney's tax-policy promises in two words:
mathematically impossible. Those aren't my words. They're the words of the
nonpartisan Tax Policy Center, which has conducted the most comprehensive
analysis to date of Romney's tax plan and which bent over backward to make
his promises add up.
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No matter how hard the Tax Policy Center labored to make Romney's promises
add up, every simulation ended the same way: with a tax increase on the
middle class. The tax cuts Romney is offering to the rich are simply larger
than the size of the (non-investment) deductions and loopholes that exist
for the rich.
http://www.washingtonpost.com/business/economy/ezra-klein-romneys-tax-promises-simply-dont-add-up/2012/08/03/66a2b1c8-dda7-11e1-8e43-4a3c4375504a_story.html