If President Obama hopes to make good on his promise to retool the U.S. health system, he'll almost certainly have to talk Congress into changing the tax treatment for employer-sponsored medical coverage.

Top administration officials acknowledge that an overhaul as sweeping as Obama envisions will require policymakers to look for new sources of money to pay for the changes -- and that the most straightforward way of making the numbers work is by confronting a provision in the federal tax code that reduced tax collections an estimated $246 billion in 2007. Senior adviser David Axelrod reiterated the message Sunday on ABC's "This Week," saying health care was too important to sink on purely mathematical questions.

The tax exclusion exempts health insurance premiums paid on workers' behalf from federal income and payroll taxes. It dates to World War II, when employers subject to wage and price controls decided to plow excess profits into health benefits in order to attract and keep workers.

The question now is how would Congress reel in the tax exclusion?

The White House is trying out a new argument to ease concerns over those sky-high estimates of the cost of overhauling the health care system. The federal government wouldn’t really be spending more money on health care, the argument goes — just shifting money that’s already in the system and spending it more efficiently.

It’s a dangerous argument for the White House to make, though, because it’s too easily shot down.

On ABC’s Good Morning America this morning, Melody Barnes, director of the White House Domestic Policy Council, used the argument to dismiss the Congressional Budget Office’s estimates that various versions of the health care bill could cost anywhere from $1 trillion to $1.6 trillion.

“I think people thinking that this is brand-new money that’s being printed,” she said. “There’s already $2 trillion worth of health care that’s being spent already. This is redirecting that money so that it’s more efficiently and effectively used and so that people are getting better quality health care.”

President Obama continues to enjoy strong public approval ratings in virtually every category, except when it comes to spending and the deficit.

And though White House strategists swear they don't fixate on day-to-day blips in public opinion, they surely are concerned that the administration's budget proposals are projected to swell the deficit above $1.8 trillion this fiscal year -- a record in dollar terms and also the biggest deficit as a percentage of the gross domestic product since the end of World War II.

So it was hardly coincidence that Obama on Tuesday took a high-profile vow of fiscal responsibility by calling for a return to statutory "pay-as-you-go" treatment for legislation. The deficit-control rules were first written into law in the Budget Enforcement Act of 1990 (PL 101-508), but Republicans who controlled Congress for most of the current decade allowed them to lapse at the end of fiscal 2002, preferring to require offsets for new entitlement spending but not for tax cuts.

Friday's news that the economy shed another 345,000 jobs in May triggered one of those "good news, bad news" moments at the White House and sent critics and supporters of the economic stimulus package (PL 111-5) into heavy spin mode one more time.

The job losses were lower than had been feared, which almost qualifies as a cause for celebration for an administration increasingly intent on demonstrating that its $787 billion pump-priming of the economy is working.

Vice President Joseph R. Biden Jr., who's minding the store while President Obama travels in Europe, met with Council of Economic Advisers Chair Christina Romer and his chief economist, Jared Bernstein, then tried to sustain the administration's careful management of public expectations in remarks to reporters.

The first family would have paid nearly $20,000 more in taxes this year under President Obama's plan to cap the deductibility of charitable contributions for wealthy taxpayers. He and first lady Michelle Obama donated $172,050, or about 6.5 percent, of their adjusted gross income of $2.66 million, to 37 charities.

Their donations are worth a deduction of $68,131.80 this year, based on qualifying for the top income tax bracket of 39.6 percent.

But under Obama's plan, which would limit the applicability of deductions by couples making more than $250,000 to 28 percent of their contributions, the first couple would only have been able to claim $48,174 in deductions, costing them about $20,000. That sum is a small portion of the Obamas' income, which they revealed by releasing their tax return Wednesday afternoon.