Anti-tax crusader Grover Norquist on Wednesday blasted a "very nice left-wing twit" who thanked him for contributing to the destruction of the middle class in the U.S.

During an interview on C-SPAN's Washington Journal, a prankster calling in on the Republican line said that he made "seven figures" and he appreciated Norquist's efforts because "I'm paying virtually nothing in taxes."

"I just find this hysterical because I don't pay any Social Security, I don't pay any Medicaid or Medicare because I exceed that limit," the man explained. "And I get capital gains so I'm only paying 15 percent."

"But I'm getting rich and the middle class is getting screwed and the lower class is getting screwed. But, hey, you know, keep it up, man, because I'm going to be filthy rich and those fuckers are going to be living in slums by the time we get done," the caller laughed.

But Norquist was not amused.

"Ralph, I think you are a very nice left-wing twit, and you're calling on the Republican line and taking up other people's time and that's really a little dishonest," the Americans for Tax Reform founder replied. "You fibbed and claimed to be arguing from a Reagan Republican perspective then made up a story about who you are -- about how you got rich and you don't pay taxes, which would be fascinating. You could make a lot of money selling that secret."

"In point of fact as people know, the top 1 percent of income earners in this country pay 40 percent of the federal income tax, the top 50 percent pay 99 percent of the personal income taxes," Norquist continued. "So we have a steeply progressive tax code, meaning we penalize people who work, save and invest."

"Your caricature of the people who don't pay taxes is silly and it's one of the reasons why people are so offended when [President Barack] Obama gets up and acts like people who have been working all their lives -- paying taxes all their lives -- are somehow not sending enough money in. You know, 'What's a matter with those peasants? Why don't they send more money in? The king wants to build a new castle and Solyndra could use some cash.' It just really irritates real taxpayers, not phony callers pretending to be Republicans."

Earlier this year, Republicans in the Senate blocked the Paying a Fair Share Act, which would have enacted a rule named for billionaire Warren Buffett, who revealed that he paid a lower tax rate than his “secretary.”

According to the Congressional Research Service (PDF), almost 100,000 millionaires in the U.S. pay a lower effective tax rate than millions of families earning less than $100,000.

An April CNN poll found that 72 percent of Americans — including 70 percent of independents — favored the “Buffett Rule.”