Grover has spent the last 25+ years getting every Republican elected to the House and Senate to sign his "Taxpayer Protection Pledge" that forbids the signer to vote for a tax hike under any circumstances and defines any change in Federal law that results in increased Federal revenues as a tax hike unless it is offset by a tax cut.
As David points out, Grover is a very smart guy who doesn't misspeak. Grover's pledge is very clear cut and Grover has made it clear that even eliminating a loop-hole violates the pledge.
My personal read is that Grover is really in a tough spot. As David suggests, the monied interests that fund Grover's operation want a way out except Grover's personal financial interests are in conflict. Once Republicans break The Pledge and the sky doesn't fall upon them, Grover becomes the emperor with no clothes. The gigs up and Grover is out of business.
Except Grover has muddied the waters again, telling the Washington Post editorial board that allowing the Bush tax cuts to expire wouldn't constitute a violation of the no-tax-increase pledge. Hard to figure how you can square that circle, but it suggests Grover is giving his pledgees an out -- even though Grover said this morning on TV that he wasn't giving anyone an out. I don't believe it.
Grover answers to some very powerful people. His outfit, Americans For Tax Reform, has long taken in big bucks from corporate players and turned around and advocated for policies, including but not limited to tax policies, favored by those same business interests. That's his business model. The contributions don't have to be disclosed, but there's nothing illegal about the arrangement. It's one the national Chamber of Commerce has basically adopted to enormous political and financial effect.
That's why Grover doesn't misspeak. There's too much money on the line. It's why people pay attention to what Grover says. Not because he is some oracle. But because a lot of smart money flows through and around Grover. My hunch is the smart money wants a way out of the debt ceiling fiasco that avoids a U.S. sovereign default. They've got way too much on the line to see their financial interests exposed to the very real risks and uncertainties that a default would cause. It's only a hunch. But Grover doesn't do anything by accident.
Grover is damned if he does, and damned if he doesn't. This couldn't happen to a more deserving guy.