In one fell swoop Wednesday, Congress’s tax scorekeeper punctured both phony claims. The analysis from the Joint Committee on Taxation also showed less wealthy taxpayers why the Buffett ruse would eventually end up exposing them to higher taxes.

With Mr. Buffett’s help, Mr. Obama promoted the fairy tale that millionaires pay lower tax rates than their middle-class employees (despite government data showing the opposite). The President then proposed to require all those making more than $1 million in adjusted gross income to pay a minimum of 30% in federal income taxes.

Senator Sheldon Whitehouse (D., R.I.) quickly drafted legislation to turn this re-election posturing into law. Joint Tax dutifully studied the bill and has delivered the official score: This year, the Buffett rule would increase federal revenues by all of $1.1 billion.

That’s less than 1 TENTH of 1% of the $1.2 trillion budget deficit Mr. Obama is scheduled to run this year. Through 2022 Joint Tax expects less than $47 billion in total new revenues from the Buffett rule while the government will be adding trillions of dollars to the national debt. Joint Tax even concedes, as it is rarely wont to do, that the rule will affect taxpayer behavior: By raising the effective tax rate on capital gains, the rule will encourage people to realize fewer capital gains.”