In all his recent interviews Mr. Bush has been modest, humorous, proud but unassuming, and essentially philosophical: History will decide. No finger-pointing or scoring points. If he feels rancor or resentment he didn’t show it. He didn’t attempt to manipulate. His sheer normality seemed like a relief, an echo of an older age.

And all this felt like an antidote to Obama—to the imperious I, to the inability to execute, to the endless interviews and the imperturbable drone, to the sense that he is trying to teach us, like an Ivy League instructor taken aback by the backwardness of his students. And there’s the unconscious superiority. One thing Mr. Bush didn’t think he was was superior. He thought he was luckily born, quick but not deep, and he famously trusted his gut but also his heart. He always seemed moved and grateful to be in the White House. Someone who met with Mr. Obama during his first year in office, an old hand who’d worked with many presidents, came away worried and confounded. Mr. Obama, he said, was the only one who didn’t seem awed by his surroundings, or by the presidency itself. …

But to the point. Mr. Obama was elected because he wasn’t Bush.

Mr. Bush is popular now because he’s not Obama.

The wheel turns, doesn’t it?

Here’s a hunch: The day of the opening of the Bush library was the day Obama fatigue became apparent as a fact of America’s political life.