For more than a decade, conventional wisdom in Washington has said that government spending can't be reduced in any meaningful way. Congress' reactions to our lagging economy have once again shown how quick fixes and the short-term politics of crisis rule the day.

However, the demographic tsunami of retiring baby boomers will, in a few short years, force Congress to act on the economic realities it has steadfastly ignored – that we are on unsustainable course and that fiscal restraint is the best stimulus.

With Senator John McCain pledging to make fiscal restraint a defining feature of his administration the American people may finally have a real debate about whether Congress should address the impending financial crisis, or ignore it altogether.

Senator McCain's pledges to veto bills with earmarks, freeze discretionary spending in his first year and to conduct a top down review of every government program represents the first serious proposal to rein in wasteful Washington spending since the Contract with America.

What Senator McCain is proposing is nothing short of replacing the parochial culture of earmarking in Congress with a culture of oversight that puts the interests of individual taxpayers ahead of the interests of career politicians, lobbyists, and donors.

One culture – the culture of parochialism – is dominated by politicians who have exchanged their oath to the Constitution for an oath to careerism, the philosophy of governing to win the next election above all else.

In the parochial Congress, which has prevailed since the early 1990s, members are supposed to compete against one another for earmarks. While politicians like to depict the states or districts they represent as "winners" in this process the fact is every state and every taxpayer lose.

For every allegedly worthwhile earmark in one state, taxpayers finance wasteful projects in 49 other states. The system is not designed to serve local communities, but to allow politicians to take political credit for spending your money.

In the other culture – the culture of oversight – the effective legislator is not the one who brings money back to their state but the one who keeps dollars from leaving their state in the first place.

In this culture, politicians serve local interest by protecting the national interest. Politicians don't look for new ways to take credit for new projects. Instead, they do the hard work of making sure programs that are already up and running work as intended.

In short, the culture of oversight leads to excellence – the Apollo Program and the Interstate Highway System, while the culture of parochialism leads to incompetence – the Katrina recovery operation and the Bridge to Nowhere.

Senator McCain understands, and recent history has proven, that Congress cannot indulge in pork while doing its primary job of conducting oversight on the trillions of dollars it appropriates every year. The ratio of earmarks to oversight hearings in Congress is indeed an accurate and sad commentary on Congress' true priorities.

For instance, in 2007, members of Congress requested nearly 32,000 earmarks. Of those requests, 12,000 received funding. Yet, for every oversight hearing held by the House and Senate Appropriations Committee, the committee processed nearly a thousand earmarks.

Congress' lack of oversight is a major cause of the more than $300 billion in annual waste in government, which is about ten percent of our entire budget (the actual amount of our annual waste is probably much higher).

In terms of scope, $300 billion could pay for the annual costs of our missions in Iraq and Afghanistan more than two times over. Our $300 billion in annual waste also exceeds the Gross Domestic Products of 85 percent of all nations on earth, including Israel, Ireland and Finland.

While both parties can and should be united against wasteful spending, Republicans have the unique opportunity to regain their status as the party of limited government. With Senator John McCain making a serious push for fiscal restraint Republicans in Congress should do him, and themselves, a favor by echoing his position.

Instead of spending the next few months asking for new earmarks, which would be vetoed with much fanfare in a McCain administration, Republicans should lead a campaign to identify specific areas of waste, mismanagement and fraud in the federal government.

By clinging to parochial pork barrel politics, members of Congress are not only picking a battle with a potential president they will lose, they are picking a battle against economic reality and history.

Sen. Tom Coburn is a Republican from Oklahoma.