The Wall Street Journal reports today on new IRS data showing that in 2006, the richest 1 percent of Americans claimed the largest share of the nation’s adjusted gross income in 20 years. The level is so high that the IRS suspects it might be the highest it’s been since the onset of the Depression. Naturally, as their income goes up, rich people’s taxes are also going down. The tax rate for the richest 1 percent in 2006 fell to its lowest level in 18 years, in large part because of the Bush tax cuts that John McCain wants to extend.