As Congress looks forward to the July 4 recess, it continues to fulfill a primary responsibility — passing legislation that funds the activities of the federal government. Five of 12 FY 2008 spending bills have passed the House and await Senate approval. But President Bush has signaled he intends to veto bills that could push spending above the $933 billion cap specified in his budget request earlier this year. Shortly after House-Senate budget resolution conferees began negotiating the spending blueprint for FY 2008, OMB Director Rob Portman warned Congress that he would recommend the president veto spending bills that exceed the president's budget request. On May 16, Portman issued a press release stating: I will recommend the President veto any appropriations bill that exceeds his request until Congress demonstrates a sustainable path that keeps discretionary spending within the President's topline of $933 billion and ensures that the Department of Defense has the resources necessary to accomplish its mission. This statement is consistent with the administration's historical insistence that annual discretionary spending be kept below the president's discretionary spending cap. But this year, President Bush faces a Democratic Congress willing to challenge his spending priorities. The White House has been careful in choosing which spending bills to sign, given the numerical imperatives the president faces if he wants to hold Congress to his $933 billion topline. For example, Portman never issued a veto threat for the Military Construction-VA ("MilCon") appropriations bill prior to certain House approval. It was not necessary for Portman to issue this threat in order to make good on his May statement, because the $4 billion by which it exceeds the president's request does not per se render a $933 billion topline mathematically impossible for Congress to achieve. How does the president's approval of MilCon comport with his insistence that spending bills remain on a "sustainable path"? The House and Senate's 302(b) allocations indicate they will approve four appropriations bills that are less than that the president's request. The total amount that these four bills are below the president's budget is $5.1 billion. This $5.1 billion budgetary wiggle room enables the president to sign a MilCon bill that is only $4 billion more than the president's request. Any additional appropriations bill that exceeds the president's request by more than $1.1 billion would render the "path to the topline" unattainable, and will, according to Portman's statements, necessarily elicit a veto. Therefore, OMB's latest veto threats on the Homeland Security and Energy-Water spending bills should be taken at face value. Congress and the president seem headed toward full-scale confrontation over purported fiscal principles. There is a $21 billion difference between his and Congress's budgets. The president's budget request is a 7 percent increase over last year's enacted spending; Congress's budget is a 9 percent increase. The president's appropriations requests may not be seen as the standard of fiscal responsibility. Since he took office over six years ago, President Bush has signed every spending bill that came to his desk, even as the national debt exploded by $3 trillion. If the president vetoes an appropriations bill, it is not clear how Congress will react. Will all the vetoes be sustained? Will Congress be forced to pass spending bills below its preferred levels to avoid blame for a government shutdown? Resolution to these questions is months way, but the president's stated position is clear: $933 billion and not a penny more.