Neither of these is good for a politician. This isn't really Bush's fault. How could he know that influential voices in the Republican Party would shift their principles on illegal immigrants so much in the short time between when Bush submitted his manuscript and when it went to press?
Bush's book assumes the conservative principles involved in immigration are more solid. It attempts to build a bridge between principle and the political moment. This is what the Republican Party needs right now: a man who advocates for time-honored truths in a new context and adapts them to changing times. But if that's your pitch—I can find the new ground—then you have to actually hit the new ground. The confusion about where Bush actually stands muddles this pitch.
Normally the writing process forces the writer to grapple with ideas. If done honestly, it makes the author feel naked and exposed until he builds himself back up again to a coherent worldview. If this were what candidates actually did, a book could be weaponry. They could brandish its ideas, hard-won from the process. That is not what campaign books are. Instead, they engage the author in a trimming exercise, an extended cogitation on how to package their ideas for public consumption. That's what campaigns are for! Books should not be campaign propaganda, or they risk become another casualty of “progress.”
The closer to a campaign a book gets, the worse it gets. That was true of Barack Obama's books. His first one, Dreams From My Father, was carefully crafted to present a specific image, but it was far more candid and authentic than the gently-gently-all-things-to-most-people Audacity of Hope produced ahead of the 2008 race.
If you find yourself in the boiler basement where any respectable second-hand bookshop stores its collection of candidate campaign books, there are a few that will help you pass the time less desperately. Goldwater's Conscience of a Conservative and John McCain's Faith of My Fathers contain ideas that don't slip out of your hand the minute you try to take hold of them. You could argue that they were written long enough before their campaigns to keep the campaign taint at bay. This loose definition of campaign book would allow you to include John Kennedy's 1957 Profiles in Courage. Yes, says the conservative, but Kennedy didn't write that. Fine, says the liberal, Goldwater didn't write Conscience of a Conservative either. Which book is more authentic? Does it matter?
If Bush simply wanted to influence the debate over immigration, he didn’t really need a book. The press hangs on his every word. Lots of conservatives like him. He’s got a huge platform. As a former governor who accomplished things in office, he has standing. He’s had to do more than just kibbitz. But candidates need to create physical books (no e-books, please) because they allow for book signings and book parties where potential voters can gather in primary states or potentially crucial swing states. Republican clubs can hold events. We all have something to give Dad for Father’s Day. They are a useful tool, but that’s not the same thing as a good book.