The IRS pulled in record income tax revenues in April. The amount was second only to the final tech boom before the bust in 2001. Now if we had record income tax revenues that would certainly imply record incomes. Record incomes would point towards -gasp- a good economy.
This might also be used as proof that cutting tax RATES can actually increase tax REVENUES. Which is really what the big government guys are all about. Of course such economic theories don't really jive with trying to drum up class warefare.