It is not NASA alone. On Tuesday 13th Bush vetoed a bill that would increase funding to the National Institutes of Health (among other things). You can argue that there is waste and deadwood in all these mega-organizations, but the NIH does good and important work. NIH funding, especially the extramural grants, is rigorously peer-reviewed and very, very competitive. Personally I think the Bush administration is locked in an essentially primitive world-view and just can’t see beyond their cumulative noses.

There is a useful article in "the Scientist" that discusses this issue.

The Scientist
(http://www.the-scientist.com/news/home/53858/)

To quote form the linked article:-
“US President George W. Bush on Tuesday (Nov 13) vetoed a spending bill that aimed to boost federal funding for the National Institutes of Health. The bill, which was passed by Congress last week, sought to increase NIH funding by about $1 billion from a 2007 budget of about $29 billion to a 2008 budget of about $30 billion.

In a statement released by the White House after Bush vetoed the bill, the president decried the Democrat-led Congress for engaging in what he called a "spending spree," and said that the legislative majority was "acting like a teenager with a new credit card."”