From the Committee  for a Responsible Federal Budget  via TaxProf:
A few months ago, we pointed out that  the Administration was cheating in its Mid-Session Review budget baseline.  Essentially it was taking policies which President Obama had signed  into law as temporary, under the stimulus bill, and assuming them as  permanent. The implication being that, if the policies were a part of  the baseline, they wouldn't need to be paid for when enacted. 
 
[T]he Administration says it should be  able to measure its policies off of a "current policy" baseline.  We disagree; if President Obama wants to extend the Bush tax cuts --  the same ones which he criticized the Bush Administration for not paying  for -- he should have to offset them, or else fess up to using them  to increase our debt. For the sake of argument, let's accept that the  Administration should be allowed to budget from a current policy baseline.  The result would remain the same—they are cheating.
 
The Administration is taking two tax  provisions from the 2009 stimulus bill -- expansions of the child tax  credit and the EITC -- and claiming them as part of the "current  policy" Bush tax cuts.
The Administration didn't inherit these  policies, they created them. And worse, still, they created them as  explicitly temporary, under a stimulus bill which they claimed was meant  only to help bring us out of this recession.
Yet the White House wants to continue  these policies, and they don't want to pay for them. So what do they  do? They hide these policies in their baseline, in the hopes that they  won't have to.  For the tax cuts, as Bob Williams of TPC points  out, they don't show this until "footnote 5 on page 170 of Analytical  Perspectives."
So how much money is involved here? Well, putting these measures into the baseline makes the President's tax cuts for families appear to cost $143 billion over ten years, when they actually cost $241 (excluding the Bush tax cuts).