As he escalates his class war re-election campaign, President Obama has taken to calling Mitt Romney's economic plan "Robin Hood in reverse" or "Romney Hood." The charge is that even though Mr. Romney is proposing to cut tax rates for everybody across the board, Mr. Romney will finance this by imposing a tax increase on the middle class. His evidence is a single study by the Tax Policy Center, a liberal think tank that has long opposed cutting income tax rates. The political left always says Daddy Warbucks gets all the tax-cut money. So this is hardly news, except that...