McConnell's remark points out that the money has still been appropriated, whether earmarked or not. However, agencies have no requirement to spend every single dollar of appropriated funds, whereas they must spend the monies earmarked for the purposes of Congress -- at least with earmarks written into the legislation itself. We may save all $7.4 billion, a portion of it, or none at all -- but we won't save any of it without an executive order canceling the Pork Christmas.
Bush has the high road entirely open to him. Congress -- both parties included -- violated its own rules and broke their own promises in airdropping 90% of the earmarks in the conference report. They can sue to get them restored, but that will put current leadership on the record acknowledging their dishonest approach to porking up the budget. Bush can go to court and point out that Congress themselves delegitimized the process used to generate these earmarks. Would they really want to answer for that?