Millions of American households are about to learn the extent of the Democratic Congress' commitment to "protecting" the middle class.
 
If lawmakers don't amend the dreaded alternative minimum tax by the end of the year, as many as 21 million filers will see their tax bills increase by an average of $2,000 next year, including some families with incomes as low as $50,000.
 
And if Congress doesn't pass a fix within the next couple of weeks, it will cause major disruptions in the filing process that could delay billions of dollars in refund checks. Treasury Secretary Henry Paulson wrote a letter to lawmakers Tuesday warning of major consequences for delaying action.
 
Reprinting IRS tax forms would take at least three weeks, and reprogramming IRS computers to reflect changes in the alternative minimum tax would take three months because the levy is tied to nearly every deduction and tax credit.
 
It should be a no-brainer for the Democratic leadership to fast-track legislation that spares constituents from a tax that wasn't intended to target them in the first place. The AMT was enacted in 1969 to prevent a few hundred millionaires from escaping the income tax altogether by claiming all the deductions and exemptions legally available to them, such as state and local taxes and business and medical expenses.
 
But the law was never indexed for inflation, and Congress has refused to eliminate the levy, instead passing one- or two-year fixes. Now millions of households, particularly those in high-tax states such as New York, New Jersey and Michigan -- Democratic Party strongholds -- are again in line for huge tax increases.
 
So what's the problem? Democrats so covet the revenue that would be generated by the AMT's expanded reach that they've insisted they need to pass $50 billion in tax increases to offset the fix.
 
"The time does come where spending money to prevent future disasters is fiscally responsible, even if it means raising taxes," House Ways and Means Committee Chairman Charles Rangel said last week.
 
It's not surprising that Congress is hemming and hawing over just how to proceed. Lawmakers will always trot out some cause or some looming crisis that requires them to spend more of your money. They can't bring themselves to rule out any tax over the long term, no matter how unfair it might be.
 
It's why the AMT hasn't been abolished. It's why Congress refused to grant the Internet a permanent exemption from taxation. It's why Congress next year will again have to take up an extension of the state and local sales tax deduction available to Nevadans and other workers who live in states that have no income tax.
 
Congress should act quickly to spare Americans -- especially the "working families" Democrats have pandered to over the past 18 months -- the punishment of flawed tax legislation. They must do it without raising other taxes. Then lawmakers should figure out how to put down the AMT once and for all.