President Bush, in a confrontation with Congress, on Wednesday vetoed a bipartisan bill that would have dramatically expanded children's health insurance.

It was only the fourth veto of Bush's presidency, and one that some Republicans feared could carry steep risks for their party in next year's elections. The Senate approved the bill with enough votes to override the veto, but the margin in the House fell short of the required number.

The White House sought as little attention as possible, with the president wielding his veto behind closed doors without any fanfare or news coverage.