The godfather of Washington tax policy isn’t a fan of the tax plan put forward by the candidate with Godfather’s Pizza on his resume.

Leading antitax advocate Grover Norquist told us on ABC’s “Top Line” today that presidential candidate Herman Cain’s now-famous “9-9-9? plan is “very dangerous,” since each of the 9 percent taxes he’s proposing could easily grow larger.

“I’m very concerned about three different taxes — every one of them can grow,” said Norquist, president of Americans for Tax Reform and keeper of the famous anti-tax “pledge” that the vast majority of Republican candidates and officeholders in Washington sign.

“To put tapeworms in your tummy to try and maintain your weight — they may have their own idea about their growth patterns and what they want to do. Creating new taxes is a very dangerous project,” Norquist said.

Norquist said he doesn’t think the 9-9-9 plan violates his group’s pledge, which Cain has signed. But he said that’s not possible to know for sure since “it’s not clearly written down, it hasn’t been scored by CBO,” a reference to the Congressional Budget Office.

“Cain has taken the pledge, he understands what that’s about. The question is about the structure of the tax rather than the total burden,” he said.

“It doesn’t create new possibilities for growth,” Norquist added. “Look, I applaud Herman Cain’s statement that the present system is too high, it’s too re-distributionist, it moves money from one side to another, let’s take rates radically down, let’s end this double- and triple-taxation of savings. But the way he does it creates these new taxes like a VAT [value-added tax] and a retail sales tax that have a dangerous history of growing.”

Norquist has come under fire from some prominent Republicans – notably Sen. Tom Coburn, R-Okla., and Rep. Frank Wolf, R-Va. – for enforcing a pledge that they argue is holding back the possibility of a “grand bargain” on the deficit, by foreclosing any discussion of additional revenues.

Asked whether there’s any scenario where he’d waive the pledge in the interest of a super-committee-produced compromise that could save the nation’s fiscal health, Norquist said it isn’t his place to grant dispensations.

“While I appreciate the attention, the pledge that the majority of the members of the House and 41 senators signed was not to me. The pledge was to their constituents that they wouldn’t raise taxes,” he said.

“The pledge is a guarantee that whatever tax reform might come out of the super-committee would be revenue-neutral. And that’s our best protection, both to require real spending restraint instead of the phony spending cuts and real tax reform.”

“I can’t say it’s okay to raise taxes — they promised their constituents they wouldn’t do it. The people who run against them in primaries and generals in the future will hold them — their voters will hold them to their commitment.”

“Tax increases on the table, spending cuts never happen. Tax increases off the table, spending cuts happen. We now know how to go forward,” Norquist said.