The situation had reached an even worse state in the waning days of former President George W. Bush’s White House tenure. In mid-October 2008, a Gallup poll found a mere 7 percent of Americans believing their nation — then dealing with a spiraling financial crisis as well as wars in Iraq and Afghanistan — was on the right track.

To some eyes, these upswings in unhappiness leave the country much more prone to volatile swings — and to populism of the left and right — than it was during more contented times.