So now they tell us that 73,764 American bridges last year were rated “structurally deficient” – the same rating as the Interstate 35 bridge that collapsed last week in Minneapolis.

That doesn’t mean all those bridges are deadly dangerous, but it does mean nobody really knows. One might think, after 7,000 years of civilization, that the governing class would have figured out how to keep bridges from killing its citizens, but evidently our betters have had other priorities.

In the meantime, a lot of cheap short-term political points will be scored on this tragedy – before we get to the long-term reality, which will be really expensive.

First, the politics: Joshua Holland, writing for the left-leaning AlterNet.org, summed up the instant liberal spin: The bridge disaster was “a predictable outcome of the rise of ‘backlash’ conservatism; we’ve swallowed 30 years of small-government rhetoric, and it’s led us to a point in which our infrastructure, once the pride of the developed world, is falling apart around us.”

Most likely, Holland was thinking back to California’s Proposition 13, the 1978 property-tax-cut initiative overwhelmingly enacted by Golden State voters. Did that tax revolt signal the “gutting” of the Golden State’s ability to spend? Let’s take a look: In 1978, the state government alone spent $18.8 billion; in 2007, it will spend $103.1 billion – more than five times as much. And that figure doesn’t include local governments, or various “off-budget” debts.

But what about the federal government? Did tax cuts favored by Ronald Reagan and George W. Bush “slash” Washington’s ability to provide for us? Let’s go to the tape: In 1980, the last year of Jimmy Carter, federal revenue amounted to $517 billion; eight tax-rate-cutting years later, in 1988, revenue came to $909 billion. Incidentally, those numbers would seem to vindicate the “supply side” argument – that lower rates lead to more economic activity, which leads to more revenue – but we can save that for another time.

But what about now? What about the incumbent presidency? In the last year of Bill Clinton, the feds took in $2.025 trillion. This year, after a string of Bush tax cuts, the supply-side magic worked once again: Revenues are projected to be $2.458 trillion – despite 9/11 and everything else. So if today’s government wanted to do so, it could pay for lots of infrastructure.

But what is the federal government’s priority these days? After the Minnesota tragedy, the president and Congress quickly coughed up $250 million for a new bridge.

So one could ask, what have the feds been up to? On CNN, Jack Cafferty declared that the cost for bridges was “a drop in the bucket compared with $450 billion wasted in Iraq.” Well, it is hard to defend the Iraq expenditures. And indeed, the $1.6-trillion “infrastructure deficit,” as calculated by the Urban Land Institute, is a daunting figure.

But during the 4 1/2 years since Uncle Sam “liberated” Iraq, he has kept plenty of money for other things; total federal expenditures, for all purposes, have been around $12 trillion. And state and local governments have shelled out an additional $8 trillion.

Of course, some folks will still insist there is “no money.” That is, after we get through with such vital priorities as Iraq and Social Security benefits for billionaires, there’s nothing left in the federal till. So such folks can then point to the larger American economy, which has generated $55 trillion in gross domestic product over the past five years. If government spending is tight as a tick, let the political class step forward and ask the taxpayers for still more money.

Because we have plenty of wealth in this country, we can afford to be safe and sound. We just need our leaders to focus close to home, on topics as boring as infrastructure and public safety.