Grover still rules the GOP with an iron fist, but there are signs that his grip might be slipping.

A small but increasingly vocal group of freshman Republicans are publicly rejecting the idea they are beholden to Grover Norquist’s Americans for Tax Reform pledge for their entire congressional careers.

One such member, Scott Rigell of Virginia, has openly rejected the pledge, explaining on his website that it would prevent Congress in some cases from eliminating corporate loopholes or government subsidies because those changes would have to be revenue-neutral. The math, he said, just doesn’t make sense.

Of course, it's not about "math" because Grover's pledge isn't about deficits or the debt. It's about keeping taxes low for rich people and "starving the beast."

Freshman Reps. Kevin Yoder (R-Kan.), Richard Hanna (R-N.Y.) and Rob Woodall (R-Ga.) never signed the pledge to begin with, making up half of the six House Republicans who refused to sign on.

Woodall argued the pledge was too restrictive because it promises that lawmakers must “oppose any net reduction or elimination of deductions and credits, unless matched dollar for dollar by further reducing tax rates.”

Make no mistake -- Grover still runs the place. But for the first time, there are a few cracks in the dam.