This mythology from both Bush and Obama about the Good Old Days™ of American politics represents revisionist history at its finest. Trump is a symptom of our broken politics; he is not, in fact, its progenitor.
George W. Bush should know better than anyone that America is not “better than this” — he endured eight years of being labeled a Hitlerian character determined to commit war crimes, a stupid monkey attempting Freudian revenge on Saddam Hussein. John McCain received similar treatment in 2008; so did Mitt Romney in 2012. Barack Obama routinely trafficked in bombast (in 2009, he infamously warned bank CEOs that he was “the only thing between you and the pitchforks”) as well as manufactured outrage (remember, Trayvon Martin could have been his son); he routinely pretended to be brave and tough (see, e.g., his overblown rhetoric about the arc of history) and yet preyed on fear (by deploying, for example, his vice president to suggest that Mitt Romney wanted to put black Americans back in chains).
For those of us who have watched politics for the past several decades, pinning the death of a common American ethos on Trump is like blaming gravity for the Hindenburg disaster: It had something to do with the problem, but the bigger problem was the enormous fire ripping through the dirigible. George W. Bush and Barack Obama did not have a common vision for America. Neither did George H. W. Bush and Bill Clinton. What’s more, the hobnobbing and backslapping of these supposed representatives of sharply varying philosophies — the notion that an elite class of political actors were playacting their conflict in public, but smoking cigars together in private — led to the rise of an outsider such as Trump.