The New York Times tells us:
In some ways, the outcome of today’s vote was not surprising; experts say it is extremely difficult for Congress to override a presidential veto. President Clinton exercised 37 regular vetoes during his eight years in office; two were overridden. Mr. Bush’s father exercised his veto pen 29 times, with one override. What would have been surprising, scholars say, would have been for Democrats to prevail.
And adds a note we've discussed before:
And in the end, the veto may not do Mr. Bush much good, especially if the bill he ultimately signs into law is not much different than the one he rejected. “It was an ambiguous victory,” said John J. Pitney, a political science professor at Claremont McKenna College in California, “because Democrats may have lost on the legislation, but they won themselves a campaign issue.”
Perhaps Democrats won.