Thinkprogress digs up all the different versions and changes of Romney's lying tax plan. They also try to explain why he had to change from one to the other as he got caught in another lie or more bath math. They provide links to all the articles about how Romney has had to lie and cover up what would really happen under is ever changing proposals.
9/6/11: Romney’s First Tax Cut For The Rich
Promising not to cut taxes for the rich, Romney proposes a plan that would extend the Bush tax cuts, eliminate capital gains taxes for those making under $200,000, cut corporate taxes, and eliminate the estate tax. In all, it adds up to a $6.6-trillion cut that would have little benefit for the middle class, which doesn’t enjoy the same benefits from a capital gains cut as the rich.
2/22/12: Romney Introduces A New Tax Plan
Under pressure from conservatives, Romney scraps his first plan in favor of the current plan, which maintains the Bush tax cuts, provides another 20-percent rate reduction for all Americans, cuts corporate taxes, and eliminates the estate tax. Romney says he will eliminate unspecified tax loopholes and deductions to pay for the plan. Romney promises he won’t cut taxes for the rich. He also promises his plan won’t add to the deficit.
2/22/12: Romney Promises To Cut Taxes For The 1 Percent
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3/1/12: Tax Plan Will Lead To $4.8 Trillion In Lost Revenue
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4/15/12: Romney Names Two Deductions He’d Eliminate
Romney tells donors that he would “probably eliminate” the mortgage interest deduction on second homes for high-income Americans, as well as deductions for state and local income taxes. That still falls far short of paying for his plan.
4/16/12: Advisers Walk Those Comments Back
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6/4/12: A $5 Million Tax Cut For Himself
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7/17/12: Media Begins To Press Romney To Name Deductions, He Refuses
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8/1/12: Romney’s Plan Would Raise Taxes On The Middle Class
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8/9/12: Conservatives Start Coming To His Defense
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8/16/12: Even With Conservative Additions, The Plan Doesn’t Add Up
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8/23/12: Romney’s Corporate Tax Cuts Also Raise Middle Class Taxes
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8/28/12: Romney Advisers Adopt Bad Math
Romney adviser Martin Feldstein writes an editorial in the Wall Street Journal dismissing the TPC analysis. Feldstein’s math, however, excludes the corporate tax cut, redefines middle class, and overstates savings that could be gained from the elimination of upper-income tax breaks.
9/12: GOP Advisers Adopt Bad Math, Part II
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9/12: Romney Cites Five Debunked “Studies” To Back Up His Plan
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9/9/12: Conservative Tax Expert Admits The Plan Doesn’t Work
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9/10/12: Romney Adviser Still Can’t Name A Deduction He’d Eliminate
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9/25/12: Romney Adviser Admits The Plan Doesn’t Work
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9/30/12: Paul Ryan Can’t Explain The Math Behind The Plan
Asked to explain the math of Romney’s tax plan on Fox News Sunday, vice presidential nominee Paul Ryan says, “I don’t have time.”
10/3/12: Romney Proposes A New Idea — It Still Doesn’t Work
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10/3/12: Romney Walks Back His Own Support
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10/3/12: Romney’s Web Site Debunks His Own Claims About The Wealthy
Romney’s campaign web site refutes his debate claim that he won’t cut taxes on the rich.
10/9/12: Romney Tweaks His Newest Idea, Making His Tax Math Even ‘Fuzzier’
On CNN, Romney adopts the idea to cap tax deductions he proposed just a week earlier. Instead of capping deductions at $17,000, he’ll now cap them at either $25,000 or $50,000. As the Washington Post’s Suzy Khimm notes, though, this makes the math of Romney’s tax plan even harder to work out. Placing the cap at $25,000, the Tax Policy Center found, would make it possible to avoid raising taxes on the middle class. It would also generate significantly less revenue. Placing it at $50,000, though, would render it irrelevant, since even taxpayers in the top 1 percent averaged only $43,208 in deductions last year.
10/9/12: Romney Needs “Flexibility”
Romney admits to the Des Moines Register that he will need “flexibility” to make his tax plan add up. At this point, it is no longer clear what tax plan Romney actually supports.
I encourage you to go read the entire article, it's short and they do a great job of hitting every point.