Count me among those shocked, just shocked: Since 2001, President Bush's tax cuts have shifted federal tax payments from the richest Americans to a wide swath of middle-class families, the Congressional Budget Office has found, a conclusion likely to roil the presidential election campaign. The CBO study, due to be released today, found that the wealthiest 20 percent, whose incomes averaged $182,700 in 2001, saw their share of federal taxes drop from 64.4 percent of total tax payments in 2001 to 63.5 percent this year. The top 1 percent, earning $1.1 million, saw their share fall to 20.1 percent of the total, from 22.2 percent. Over that same period, taxpayers with incomes from around $51,500 to around $75,600 saw their share of federal tax payments increase. Households earning around $75,600 saw their tax burden jump the most, from 18.7 percent of all taxes to 19.5 percent.