If McCain's opposition to Bush's tax cuts was based on the unseemliness of letting deficits balloon for the benefit of top earners in a time of war, then his opposition should have grown stronger. Instead, it grew weaker and then collapsed. Since McCain's votes, we have witnessed budget surpluses turn into projected $400 billion annual deficits.

With the public debt expanding, corporate profits near records, and family incomes down since 2001, McCain has made his signature economic proposal a corporate tax-relief package that will cost $2 trillion to $3 trillion over 10 years. In the New York Times on June 1, former Bush economic adviser Greg Mankiw defended this indefensible fiscal policy by pointing to two purely theoretical studies to posit that lowering the corporate-tax rate by a third is really about helping typical workers. This is more regressive than the policies that led McCain in 2000 to blast Bush for having "38 percent of his tax cut go to the wealthiest 1 percent of Americans."

Mankiw paints an even more incomplete and distorted picture of the fiscal impact. He says McCain's plan to cut the corporate- tax rate from 35 percent to 25 percent will cost only $100 billion a year in lost revenue, but benefits to the economy will cut that cost in half. Yet, even the Bush Treasury Department suggested that the costs of a smaller corporate-rate cut -- from 35 percent to 28 percent -- would cost at least $130 billion annually.

The McCain camp instead offers vague and unrealistic promises to cut unspecified spending and eliminate earmarks. McCain makes a lot of this last point, even though banning earmarks would only pay for less than a half of 1 percent of his high-income tax-cut proposals. Where have you gone, fiscally responsible John McCain?