It's September. All that is left are the interminable campaign commercials, the debates and the voting. Candidates all over the country are vying to lead governments with major problems that the candidates will need to address starting the day after they are elected. Unfortunately, the recent national political conventions, with the official nominations of former Massachusetts Gov. Mitt Romney and President Obama, once again highlight the vast gulf between campaigning and governing.

Arguably (and I don't say this just because I teach budgeting for a living), budget management is one of the most important things--perhaps the most important thing--that any chief executive has to do. In the current economic environment, governors, mayors and the president, once elected, will confront major budgetary challenges. Addressing these problems will require creativity and flexibility. Unfortunately, political campaigns increasingly seem to contradict this need by issuing all sorts of ill-advised pledges and promises that just make it more difficult to govern.

To illustrate this, let's go back to Gov. Romney and President Obama. The federal budget is a mess, both substantively and procedurally. Debt held by the public, already at a postwar record level of 68 percent of GDP in 2011, will rise, under reasonable assumptions about the continuation of current policies, to almost 100 percent of GDP within 10 years, and could approach 200 percent of GDP by 2040 (that's about twice the current level of Greek or Italian debt). Moreover, Congress has abdicated its responsibility by failing to enact an overall budget for the last three years, and has not passed appropriations bills on time in 15 years.

Various commissions, including the president's own deficit commission, the Bipartisan Policy Center's Debt Reduction Task Force and the Peterson-Pew Commission on Budget Reform, have studied the budgetary challenges facing the country. They have come to two consistent conclusions. First, the sooner we act, the easier it will be to avert economic disaster. Second, the magnitude of the problem requires that all options--reforming Social Security and Medicare, cutting defense (not a little, but a lot) and domestic spending (not a little, but a lot), and raising taxes--be on the table.

We should, then, be having a national debate about budget priorities: What do we do to get ourselves out of this mess? An honest discussion would communicate that we probably will have to pay more to, and receive fewer services from, the federal government in the future if we are to avoid a debt crisis.

Will the campaign be the great national debate about how to do this? It is doubtful. Maybe, as New Jersey Gov. Chris Christie suggested at the Republican convention, the election will be about telling people the truth about the nation's problems and how to address them. Or it may follow more recent precedent and rob the next president-- as he makes promises in pursuit of enough votes in Ohio, or Virginia, or Pennsylvania--of the flexibility he will need to address the problem. If the latter, the campaign is likely to degenerate into what I would call "dueling pledges." Consider the following:

• The candidates have already promised not to raise taxes, on either anyone (Romney) or the middle class (Obama).

• Both candidates have already pledged, implicitly or explicitly, not to touch Social Security. Some advisers to the president have bought into the rhetoric that Social Security is not part of the problem, and even Paul Ryan's budget plan doesn't make any changes to this program.

• At least one candidate (probably both) is likely to feel the need--say, while campaigning in Florida--to promise not to cut Medicare (or at least not soon, and not much), in spite of the fact that health-care costs are eating the federal budget alive.

• The two candidates will likely even box themselves in, in relation to what is left, by promising not to cut the defense budget (Romney) or not to forego needed investments in education, transportation and energy (Obama).

My focus here has been on the federal budget because the gap here between necessary reality and probable campaign rhetoric is most stark. But all over the country during this campaign season, candidates are being pressured to promise not to do things. The larger the budgetary problems that face a given government, the more problematic it is for politicians to tie their hands before they are elected.

I think it would be nice if candidates for office, starting now, would take a pledge (recognizing the irony, of course) not to take pledges. These promises, which many of the candidates realize represent the worst form of pandering, both rob them of the flexibility they need to address serious problems of governing and encourage them to be dishonest with the voters at the same time that they are encouraging these same voters to trust them to lead government.