Why Hillary should fear optimism

Instead of reasons for hope, the Democrats offered these voters bromides about optimism: America’s best days are always ahead of it, etc., etc. These bromides came with a liberal spin, the genius of America being defined as its closer and closer approximation of egalitarian ideals. The idea that American patriotism consists of loyalty to a future country clearly speaks to many of our citizens. Will it be enough in an anxious era, when Americans are deeply dissatisfied with their politicians? And when Mr. Trump is offering a more pointed explanation of that dissatisfaction than the Democrats are?

The Democrats’ optimism about the country is tightly related to their optimism about their own political fortunes, which is based on demography. They represent growing demographic groups — including nonwhites and the unchurched — rather than shrinking groups like the white working class. But that optimism is unlikely to prove contagious among that group.

And the Democrats’ rhetorical optimism is vulnerable to events in a way Mr. Trump’s is not. Terrorist attacks and high-profile crimes may not make Americans find new virtues in Mr. Trump, but they will validate his campaign message and make the Democrats’ look naïve or worse. Mrs. Clinton said in her speech: “There is no other Donald Trump. This is it.” That’s right: We know his campaign will focus on her alleged incompetence and crookedness. What we don’t know is how well she will be able to adapt to Mr. Trump’s unusual pursuit of the presidency.