Over the years, the ability of Congress and the White House to play this mutual back-scratching game has diminished for various reasons. A key one is that Congress passes many fewer bills than it used to. Legislating tends to be done largely by amendment to large bills that are harder to veto.

This has increased Congress's power relative to the president, but it has also cost Congress the opportunity to play the Dole game. It is harder for it to say no to anyone, giving rise to increasing numbers of pork-barrel projects and special deals that are unjustified on public policy grounds. This is why Bush has repeatedly asked for line item veto authority.

The problem is that it isn't only in appropriations bills where problems lie. Moreover, much of the waste in this area is already under the president's control because the spending is specified in what is called report language that does not carry the force of law. Bush could in effect veto this stuff now if he wanted to. Because of his support for so many big spending initiatives, such as the Medicare drug bill, Bush lacks credibility as a guardian of the public purse, making it appear as if his calls for a line item veto are just a way of diverting attention from his own failure to control spending.

In response, the White House points to the fact that Bush often issues veto threats -- 135 times through May, according to the Office of Management and Budget. But with no actual vetoes ever forthcoming, such threats have lost a great deal of credibility over time. Congress now mostly ignores them.

It has always amazed me that a president who understands so clearly that diplomacy must be backed by force to be effective in the international arena should be so oblivious to the fact that the same thing applies domestically as well -- veto threats must be backed by actual vetoes from time to time if they are to be credible. I believe that just one veto of a spending bill back in 2001 would have saved the nation from tens of billions of dollars of wasted spending.

When conservatives complain to the White House about its veto-phobia, they are always told that Republican control of Congress is the main reason. But as Brookings Institution scholar Kathryn Dunn Tenpas points out in a new paper, in the postwar period, presidents before Bush averaged two vetoes per year during times when their own party controlled Congress. Bush is clearly an anomaly.