Let's be clear: Rep. Mark Kirk has never been a moderate on economic policy. After all, it was Kirk who in the past month blasted President Obama's budget for running up short-term deficits and slightly reducing the home-mortgage-interest deduction (an extremely regressive tax break that only benefits the nation's wealthiest individuals). Now, according to Greg Hinz, the North Shore Republican will further brandish his conservative credentials -- possibly in preparation for a statewide run -- by holding a press conference today to denounce none other than the estate tax.

Set to expire next year without congressional action, Republicans have long decried the tax as a burden on family farms and small businesses.  We can expect Kirk to repeat this argument.  But as the Center for Budget and Policy Priorities (CBPP) points out, a 2005 Congressional Budget Office analysis found that "exceedingly few family farms and small businesses face the estate tax":

The CBO report found that if the current exemption level of $2.0 million had been in place in 2000, only 123 farm estates and only 135 family-owned businesses nationwide would have owed any estate tax.  The number of taxable farm estates drops to 65 nationwide at a $3.5 million exemption level, the level that takes effect in 2009.  The number of taxable family-owned business estates falls to just 94 under the $3.5 million exemption. 

The CBO report also found that of the few farm and family business estates that would owe any estate tax, the vast majority would have sufficient liquid assets (such as bank accounts, stocks, bonds, and insurance) in the estate to pay the tax without having to touch the farm or business.  For instance, of the 65 farm estates that would have owed tax under a $3.5 million exemption, just 13 would have faced liquidity constraints.

Conservatives have also reframed the measure as a "death tax," thereby obscuring it's original purpose: taxing the previously un-taxed wealth of the ultra-rich. But the truth is that the estate tax largely avoids income already taxed during the decedent's lifetime. More from CBPP:

99 percent of estates pay no estate tax at all, primarily because the first $1.5 million of any estate's value ($3 million for a couple) is entirely exempt from the estate tax.  Thus, 99 percent of estates cannot face double taxation under the estate tax for the simple reason that they owe no estate tax.

For those few, large estates that do owe estate taxes, a substantial proportion of their assets have never been taxed.  Indeed, the majority of assets in estates valued over $10 million consist of untaxed capital gains -- that is, property, stocks, and bonds that have appreciated in value since they were first purchased by the decedent but have never been subject to tax.

If fully repealed, the government would squander a substantial amount of revenue -- the Wall Street Journal pegs the figure at $500 billion over 10 years. If it's the national debt that Kirk is concerned about, rescinding this measure doesn't seem like the most prudent economic decision.