“What’s the most important quality or qualification the next president, whoever he is, should look for in a treasury secretary?”

Treasury Secretary Timothy Geithner was initially reluctant to answer that question from George Stephanopoulos on ABC’s “This Week” four days ago. But after the host persisted, Mr. Geithner replied: “Well, I think it’s very important that you have somebody who’s willing to tell him the truth and, you know, help him do the tough things you need to do in these — in these jobs.”

And to his credit, Mr. Geithner delivered some hard truths during that interview, including: “It’s obviously still a very tough economy out there.” ... “Unemployment is still very high. And until that comes down, income growth is going to be very — very soft, very weak.” ... “A big part of the burden for a sensible long-term fiscal plan is going to fall on middle-class Americans.”

OK, so Mr. Geithner balanced those glum assessments with some upbeat remarks, as in: “The broad indicators are pretty encouraging.”

Yet the secretary’s acknowledgments that America’s economy is still struggling — and that our nation will never solve its alarming long-term debt problem by simply raising taxes on the rich — are indisputable truths.

Those are also inconvenient truths for President Barack Obama and fellow Democrats now pitching the myth that our nation is going broke because the wealthy aren’t paying their “fair share.”

Back in September when the president unveiled his “Buffett Rule,” which would raise taxes on incomes of $1 million to 30 percent, he said it would “stabilize our debt and deficits for the next decade.”

Confronted by facts that debunk that preposterous claim, the White House has since backed off from it. As Mr. Stephanopoulos reminded Secretary Geithner Sunday, the administration’s “own numbers” show that the Buffett Rule “would raise only about $5 billion a year.”

That’s chump change compared to a federal deficit of at least $1.29 trillion in each year of President Obama’s watch as the record national debt has soared to, as of Wednesday, $15.67 trillion.

Mr. Geithner defended the Buffett Rule as a “modest increase” in taxes on the rich “as part of a very comprehensive, detailed, long-term fiscal program that would bring our deficits down to a sustainable level.”

Huh? What “comprehensive” program?

In a remarkably revealing exchange with House Budget Committee Chairman Paul Ryan, R-Wis., two months ago, Mr. Geithner uttered this defining truth about the White House’s performance on the debt mess: “You are right to say we’re not coming before you today to say ‘we have a definitive solution to that long-term problem.’ What we do know is we don’t like yours.”

What we also know is that Mr. Geithner is right about the importance of a treasury secretary telling the truth.

And the truth is, we appreciate the secretary’s candor — but not the Obama administration’s bottom line.