A budget as progressive and ambitious as President Obama’s 2010 proposal doesn’t just pay for itself. And to cover the potential investments in health care, energy, and education, the White House has signaled it is willing to reverse the course set by Ronald Reagan and George W. Bush and gradually raise taxes on the nation’s wealthiest individuals.

Obama officials have been adamant that any tax hike would be delayed until 2011, when the recession will presumably have ended. But GOP Rep. Mark Kirk is already on the attack. Appearing on FOX Chicago Sunday yesterday, he lamented the fact that the White House plans to generate new revenue by targeting the home-mortgage-interest deduction:

As is customary, Kirk leaves out some crucial details about this tax break.

For one, the Obama administration policy will only affect households in the top two income tax brackets. More specifically, families with taxable earnings of $208,850 or more will soon be able to deduct only 28 percent of their interest payments as opposed to the 33 or 35 percent rates they currently claim. As the Wall Street Journal explains, “[A] taxpayer in the top bracket paying $1,000 of mortgage interest, for example, would see a tax break worth $350 reduced to $280.” In exchange, the government would net an estimated $318 billion over 10 years. Seems like a worthwhile trade-off.

What’s more, the mortgage interest deduction isn’t even sound public policy to begin with. Harvard economist Edward Glaeser issued this substantive take down in late February. Among its larger problems: The size of the tax benefit is proportional to one’s debt (meaning the government is effectively subsidizing people to gamble on their home investment), the deduction drives up prices in places where the supply of new homes is constrained, and it’s wildly regressive:

The tax savings for households earning more than $250,000 is 10 times the tax savings for households earning between $40,000 and $75,000 a year, according to recent research by James Poterba and Todd Sinai.

Slate’s Daniel Gross lambasted the regressive nature of the tax break back in 2005,:

[I]t’s remarkably unprogressive. One of the biggest obstacles to homeownership is the inability to come up with a down payment. The deduction doesn’t help you there. Taxpayers who don’t itemize deductions—generally people in the lower income brackets—don’t receive any benefit from the home-mortgage deduction. And the more you borrow, and the higher your tax bracket, the more valuable the deduction becomes.

It's interesting that, out of everything in Obama’s first budget, this is what Kirk decided to crow about.