The recent brouhaha about a government study showing that women should get fewer tests for breast and cervical cancer is a great example of how tough it is to cut government spending. The government is now almost entirely Democratic, and all we hear from the other side is that this is a horrible example of how the Democrats will ration medical care under federalized medicine. I don't think it's a stretch to say that if this had occurred in 2004, it would have been loudly decried as an example of the heartless Republicans trying to cut government services by removing some Medicaid services for poor women. In either case, government doing less is used a political cudgel against those doing the cutting, even if the cutting makes sense. (I don't know the details of the study in this case, but my point is that the details don't really matter in the political debate.)
This is why any increase that is funded by "cuts to be named later" should be evaluated as if those cuts will never occur, because, as we see over and over, those "cuts to be named later" almost never happen. What I'd give for a government that does the cuts first. Particularly out here in California.