In his weekly radio address Saturday, President Barack Obama again urged Republican lawmakers not to use the debt ceiling as a negotiating tool for budgetary concessions. Citing the 2011 showdown on this issue, he warned: “The last time Congress threatened this course of action, our entire economy suffered for it. Our families and our businesses cannot afford that dangerous game again.”

That’s a familiar pitch from this president as another debt-ceiling deadline looms at some point from Feb. 15 to March 1.

Yet in 2006, when President George W. Bush sought a debt-ceiling boost of his own, a U.S. senator made this powerful case against that request:

“The fact that we’re here today to debate raising America’s debt limit is a sign of leadership failure. Leadership means ‘The buck stops here.’ Instead, Washington is shifting the burden of bad choices today onto the backs of our children and grandchildren. America has a debt problem and a failure of leadership. Americans deserve better. I therefore intend to oppose the effort to increase America’s debt limit.”

That senator was Barack Obama of Illinois.

The national debt was then $9 trillion.

Today, the national debt is $16.42 trillion and rapidly climbing — as it has during Mr. Obama’s entire White House tenure.

Mr. Obama’s 2006 condemnation of “a failure of leadership” on our nation’s “debt problem” was on the fiscal-responsibility mark. Under the second President Bush, federal spending — and debt — rose steeply, elevating the deficit to what was then a record $455 billion during his final year in the White House.

However, during Mr. Obama’s presidency, the deficit has soared to more than $1 trillion every year. And now he insists that the debt ceiling be raised again without substantial spending cuts.

Pundits dwell on whether Democrats or Republicans come out ahead in the polls when budget battles go to the brink, as in the year-ending “fiscal cliff” drama. President Obama somehow emerged as the public-relations winner on that one — for now.

But Americans across party lines will be the ultimate losers if our national government doesn’t finally learn to live within our means.

So don’t think of the debate over the next debt-ceiling increase as just another premise for partisan bickering over spending — and taxing — choices.

Think of it as an alarming reminder of our unsustainable fiscal folly — and of the “failure of leadership” that is still postponing the tough decisions necessary to restore America’s bottom-line viability.