The last paragraph in the article reads:
If Mr. Obama does succeed in raising tax rates on the rich, we'd also wager that the rich share of tax payments would fall. The last time tax rates were as high as the Senator wants them -- the Carter years -- the rich paid only 19% of all income taxes, half of the 40% share they pay today. Why? Because they either worked less, earned less, or they found ways to shelter income from taxes so it was never reported to the IRS as income.
So are you saying that the wealthy are not presently finding ways to shelter income from taxes so it is never reported as income?