Even as Senate and House negotiators go to work yet again on a budget extension, figures abound on the true cost of a government shutdown. Some say $100 million a day, others say $8 billion a week, and still others predict a significant market correction as investors wonder whether the shutdown might provoke a debt crisis.

There is real money at risk for sure, but none of the estimates get to the deeper impact on public confidence in government as backlogs increase, regulations stall, inspections stop and federal parks close. As the Washington Post’s Ezra Klein writes, the real damage from continued impasse involves plain-old uncertainty. Another last-minute agreement might be a reassuring sign that Congress and the president can actually take action, but a shutdown confirms the sad reality that Washington has become so dysfunctional that it can’t even fund itself.

There is also the human impact as veterans wait for their benefits, patients wonder whether drug trials will stop, contractors put their work on hold and ordinary Americans start thinking about everything from health insurance to retirement checks. It doesn’t matter whether anyone is right to worry--Social Security will continue to pay benefits just as it always has. What matters is that Americans and the world get another dose of disquiet about government’s ability to act.

Ordinarily, this cost would be easy to spot in surveys of trust in government. That’s where public angst usually shows up. But trust in government to do the right thing is already so low that it’s hard to see how a shutdown would further corrode confidence. Congress can’t fall much further, and President Barack Obama’s approval will take a hit as Americans put a pox on all the federal houses.

Not everyone thinks a shutdown is such a bad thing, of course. According to a mid-March CNN/Opinion Research Corporation poll, 36 percent of Americans think a few days of shutdown would be a good thing, and 24 percent think a few weeks would be just as good. So what if the national parks close? The state parks are still open, right?

The impacts may not show in the already dismal levels of trust in government, but they will surely register in the growing doubt that Washington can execute the laws. Americans don’t want another egg recall, but a shutdown increases the odds that the food safety system will fail again. They don’t want another deepwater oil spill, but a shutdown increases the odds of just that. They don’t want shady investors to benefit from failed oversight, but a shutdown increases the odds of another Ponzi scheme and further insider trading.

Look down the list of recent government breakdowns, and every one was tied to the abrogation of constitutional responsibilities now in play on the budget. September 11 revealed a failure of imagination, Enron showed a lack of oversight, the flu vaccine shortages an absence of careful planning, Hurricane Katrina an evisceration of federal leadership, the Fort Hood shootings a breakdown in monitoring, continued contract fraud a careless disregard of the law in the absence of enforcement, the Christmas Day bombing plot another failure of imagination, the Walter Reed scandal a lack of investment and concern, the Massey mine disaster and Gulf oil spill a complete abandonment of the rule of law, and the financial collapse a triumph of greed in the absence of checks and balances.

A government shutdown merely builds momentum for another round of failure, and an acceleration of doubt. With federal employees hunkered down wondering whether they can spend a dime on enforcement or performance, Congress wasting precious time claiming credit for protecting taxpayers while doing just the opposite, the president pinned down by a new war in Libya and reluctant to lead, and the world both literally and figuratively on fire, a shutdown would raise the most dangerous doubt of all--that the United States and its own citizens cannot be trusted.

If the U.S. cannot pass something as simple as a six-month budget extension, if it cannot do so without taking the nation to the edge of yet another shutdown, and if it cannot bring itself to judgment without the threat of another economic collapse, then how can it be trusted to provide clear leadership in these desperately uncertain times?

It is a question that Tea Party members should be asking. A government shutdown is just another way of saying the U.S. doesn’t work. That can’t be any comfort to any of us. Instead of calculating which party wins and loses in the childish bickering on Capitol Hill, the nation’s leaders should send a resounding message to the world that we’re still in business and take the Constitution seriously.

More from On Leadership at The Washington Post:

The federal worker’s guide to a shutdown

Managing stress in agencies amid the budget uncertainty

The president’s definition of leadership