In spite of never ending criticism of Bush by many in the press and in spite of blind-eyed fawning adoration for Obama by that same group, over time reality wins out.
And in spite of the spin by the likes of hawcraper the is based more the sobering up from mass hysteria favorability and shedding of baseless guilt when viewing Obama.
I.E. we were tired of the Bush style after eight years, but despite his flaws when compared to Obama he doesn't look so bad. If the press coverage flipped to reality then Bush would have a comfortable double digit lead.
Time seems to favor reality, and while most ex Presidents' popularity does rise over time, for context, Clinton's actually fell.
When the facts come out written by honest historians, not reconstructionist liberals, Bush's popularity will rise, while the facts will cause Obama's rankings to fall.....to one of the lousiest Presidents in American history.