Not for one instant should anyone doubt the shrewdness of George W. Bush's presidential campaign. Sure, the guy may flunk some pop quiz on a TV show. But when it comes to the big things, W. and his operatives know exactly what they're doing.

Why did Bush choose to release his whopping tax-cut plan on the eve of Thursday's debate in New Hampshire? The obvious reason was that in the tax-cut-friendly Granite State, he needed a big plan to counter Steve Forbes's endless talk about flat taxes and abolishing the IRS.

But there's more. This period is Bush's debate blitz, first in New Hampshire, then last night in Phoenix and a week from now in Des Moines. Debate analysis is notoriously heavy on style points. It's not a time for detailed discussions of grubby matters such as tax cuts--even though what a president will do about taxes and programs matters a lot more to average voters than what the pundit class thinks of a quip about Alan Greenspan or that nice word Bush said about John McCain.

As a result, Bush could see the details buried, and put two spins on his plan--one for public consumption, the other for the arbiters of tax-cutting purity within the conservative movement. For now, Bush is managing to have it both ways.

For the public, the key words in Bush's well-drafted tax speech were his promises to "take down the toll gate on the road to the middle class" and to "treat the middle class itself with greater fairness." Message: This tax plan is no giveaway to the rich. It's for hard-working folks just like you.

But the tax purists care most about cutting "marginal tax rates," meaning in particular the tax rates on the very well-off. One key to creating the budget surplus was President Clinton's willingness to raise the rate on the very wealthy to 39.6 percent. Republicans have been trying to bring it down ever since.

Bush does that by cutting the two top rates to 33 percent. To make sure the purists got the point, Bush met with the editors of the Wall Street Journal editorial page--they constitute the Sacred Congregation for the Doctrine of the Faith in supply-side circles--and sold them on the idea that this tax cut was the very best they could expect in these political times. According to the Journal's Paul Gigot, Bush also assured them he's not averse to more tax cuts. "It's the beginning. It's not the end," Bush said of his plan.

The selling worked as well with Grover Norquist, the president of Americans for Tax Reform. Norquist arbitrates tax-cut matters for the conservative movement much as Martha Stewart arbitrates style questions for the upper middle class. Bush more than passed. "He put serious reductions in marginal tax rates, Ronald Reagan-style, back on the table," Norquist said in an interview. "What Bush put together is a tax bill like the Republicans put together this summer."

Bingo. The congressional tax cut--$792 billion over a decade--did not sell with the public, according to the polls and to many Republican politicians. Now Bush thinks he can sell an even bigger plan (independent estimates put its 10-year cost at between $1.3 trillion and $1.7 trillion) by including some extra goodies for the middle class.

But the net result, according to Citizens for Tax Justice, is still a big bonus for the wealthy, especially when you consider that Bush would eliminate inheritance taxes on large fortunes. "Almost two-thirds of Bush's proposed tax cuts would go to the best-off 10 percent of Americans," the liberal group concluded.

Bush and his advisers knew one other thing: that the strategy of millionaire flat-tax impresario Steve Forbes rests on getting to Bush's right on taxes. If Bush had proposed selling off the Capitol, the White House and the national parks to bring tax rates down to zero, Forbes would still have to say he hadn't gone far enough.

Forbes played his assigned role, calling Bush's tax plan too timid. Bush could hardly wait for his ever-so-cautious moderate moment. "For some, it's not enough," he said happily. "And for some, my tax cut is too big. Which leads me to believe I may be doing something just right."

Indeed he is. Among the Republican candidates, only McCain has been willing to suggest Bush's tax cut may be too big. Unless McCain presses the issue, Bush may waltz through this month without having to explain why a tax approach that's flawed when congressional Republicans propose it is the soul of reasonableness when it's put forth by a shrewd, smiling "compassionate conservative."