An old tax friend, Bruce Bartlett, has just published a book about President George W. Bush titled “Impostor.”

I admire Bruce. He’s been my buddy and my tutor. Over a decade of phone calls, he taught me about Eisenhower’s top marginal rate and Germany’s value-added tax. We fought together for tax cuts. Even more important, Bruce looms large in Washington, and his ideas warrant coverage.

Still, “Impostor”? The title suggests that the president intends to deceive.

The charge troubled me enough that I managed to lose the book – several times. Sure, the Bush administration committed a huge error when it created the senior-citizen drug program. Bush’s Treasury secretaries wobble on the dollar. Bush lacks the will to make enemies necessary in a president and he never vetoes. And yes, Bush agreed to spending that might cause future tax increases.

But Bush’s economic policy has been good enough to keep the U.S. competitive. It has increased productivity. Bush, unlike many presidents, actually understands the importance of entrepreneurship and does something about it. You may not like the result, but lying is not a big part of the story.

So I e-mailed Bruce questions. There isn’t room for all the answers, but here are some of them:

AS: Bruce, is your analogy of Bush and Richard Nixon really fair?

BB: Absolutely. Almost all the really bad big government stuff enacted since LBJ was done by Nixon. And every time conservatives complained, he either ignored them or said that fighting the war took precedence. Bush treats the conservative movement with the same casual disdain.

AS: Bruce, are you not worried about personal loyalty?

BB: My loyalty is to the ideas I believe in and secondarily to those who espouse them. When they stop espousing them, they have no further claim on my loyalty.

AS: Bruce, what is the difference between you and David Stockman?

BB: Stockman was an employee of Ronald Reagan who came to disagree with his policies. The proper course for him was to quit. Instead, he sabotaged Reagan from within. I have done nothing remotely similar. I have never worked for George W. Bush and I have never sabotaged from within. Everything I have said and done is in the public record.

AS: Bruce, my problem is I like you and admire your work, but I think you are too harsh on the Bush administration.

BB: I think I was actually too easy on it because I completely ignored the Iraq mess and non-economic domestic policy mistakes. Also, a number of screw-ups such as Katrina and the (Harriet) Miers mess came after I finished the book.

Bruce’s answers all sound persuasive, especially the part about the limits of loyalty. If “loyalty” were a stock, it would have a low price now. Journalists tend to think “loyal” and “stupid” are synonyms. Josh Bolten, the former Goldman Sachs Group Inc. executive, was named White House chief of staff this week. The main criticism was that he was an insider and a loyalist.

The marketplace of ideas currently places a premium on inconsistency. The fact that one’s actions can’t be predicted makes one seem fascinating. Maybe they got it from teenagers, but journalists love to be random.

Still, neither Bruce’s case, nor his thoughts about personal loyalty, convinces me. Personal loyalty can make for better journalism or policy, occasionally. If people trust you, they tell you things that your readers need to know. A policymaker who doesn’t know anyone doesn’t have any allies to get his legislation passed. What’s important is recognizing the limits of personal loyalty: when your friend does something really wrong, you reconsider.

As for loyalty to ideas, it matters more. Thanks to its loyal adherence to the ideas of people like Bruce, the Bush administration didn’t hurt the economy during the recent recession. If Bush truly were a Nixon, he would be doing damage. He would be bullying steel companies into lowering prices, or instituting a mandatory freeze on wages and prices, as Nixon did in August 1971. He would be pressuring Ben Bernanke to inflate and laying the ground for a decade of stagflation.

Another weakness in Bartlett’s argument is that he assumes Bush runs the economy in isolation, like a French king. In fact any president’s domestic policy life is one long haggle with Congress, including fellow Republicans; the farm bill was awful, but it would have been worse had Charles Grassley of Iowa had his way.

Assailing a second-term president on policy scores lots of points with the public. But when the press attacks the Bush administration on, say, an immigration plan or one to reduce tariffs, it reduces the likelihood that the administration will have the courage to push those plans through. That may be the desire of the journalist. But to deny that you yourself are helping lame the duck is disingenuous.

So here’s what I think about Bartlett and Bush. Bruce is not disloyal at all, not to the ideas, at least as he conceives them. But he is wrong. The U.S. economy this decade made Europe into one giant Envy Land. Bush is no Reagan, but he is no Nixon either. Some American economic success is due to that big-spending Congress, some to Bill Clinton, some to the Federal Reserve. And some – call me a naive loyalist fool for saying it if you like – actually goes to George W. Bush.

Miss Shlaes is a columnist for Bloomberg News.