No American president in memory has ever had a more ambitious agenda with less money to pay for it than Barack Obama.

What we are seeing today in his willingness to consider breaking his campaign promise on raising taxes will be just a start. His administration will almost certainly be characterized by a long and grim quest for tax revenue. There will never be enough. Partly that's because Mr. Obama inherited a badly damaged economy with an already swelling budget deficit.

But he chose to address it by letting Congress write a staggering spending bill that deepened the deficit, while doing little so far to boost the economy. A shrinking or sluggish economy means declining tax revenues, which means a deeper deficit and an ever growing need for more revenue. The president talks a lot about savings, but the spending path remains sharply upward.

It was almost amusing last week to watch his Senate allies struggling to keep their version of his health care reform plan down to a mere trillion dollars over ten years. From where we are headed today, there is simply no way to tax this economy out of its hole. What the administration needs is a booming economy with the gusher of tax receipts that will bring. But higher taxes are the enemy of that, inevitably producing less revenue than expected, and renewing the impulse to raise taxes even further. This lesson has been taught before, but needs to be taught again. It will be.

Brit Hume is the senior political analyst for FOX News Channel.