With the certainty of the tides, the media is awash with invidious comparisons between George H.W. Bush in death and Donald J. Trump in the White House. From the anti-Trump metronomes at the Washington Post there was this: “Trump’s time in office, by contrast, has been defined by a war against virtually all of the norms and institutions that Bush held dear.”

Manifestly, George Bush’s death has put in motion a nostalgia for something lost. And it is a nostalgia that appears to be bipartisan. What has been lost, however, predates...