However this election turns out, the 2016 campaign for the White House will undoubtedly be remembered for its vulgarity, mean-spiritedness and mendacity. It has been a national embarrassment. But a parallel failing is less noticed: the unwillingness of both candidates — Hillary Clinton and Donald Trump — to come to grips with national problems that are staring them in the face but involve unpopular political choices. I refer, of course, to an aging society and immigration.

The most obvious is an aging society. In 1990, those 65 and over comprised 12.5 percent of the population; now, according to Census Bureau projections, that share is racing toward 16 percent in 2020 and 19 percent in 2030. That's one in five Americans. Already, federal spending for older Americans (mainly Social Security, Medicare and nursing home care under Medicaid) dominates the national budget. It's crowding out spending on other programs, from defense to parks, and is the chief source of chronic budget deficits.

Nor is that all. The economy's slowdown reflects in part the retirement of millions of baby boomers, whose exit from work reduces labor force growth. The generational unfairness is palpable. Younger Americans are seeing more of their taxes diverted to care of the elderly, who often are in better financial shape than the young who are subsidizing them.