The transition after the Vietnam War to an all-volunteer force created the world’s finest professional military. But it also reinforced geographic and cultural divisions that reveal themselves in our voting. One recent paper found that in lower- and middle-income families, children with higher test scores are more likely to enlist, while the opposite held true for upper-income families. In communities like mine, we send our best and brightest to our armed forces. Our culture’s elites, on the other hand, encourage their children to do just about anything else.

To serve in the modern military — or to be the uncle, parent or sibling of one who does — is to treat the necessary service and sacrifice of war with a sacred honor. In my community, we pile into cars and drive hundreds of miles to watch our children’s graduation from basic training. We shed tears of sorrow when we drop them at the airport to go to war and tears of joy when we pick them up after they’ve returned unharmed. We take our brother to church and ask our pastor to pray for his safety. We fight on the phone with our wife’s health care provider at Veterans Affairs. We wonder whether that temper a friend developed in Afghanistan is evidence of a long-term mental health problem.

Admirably, most Americans have managed to separate their political feelings about a given conflict from their appreciation for those who served. But the chasm remains, even while most of our fellow citizens enthusiastically support the troops. They see our Middle East wars as political issues to understand and debate, not as the signal moment in the lives of the people they care most about.

Predictably, this division has also infected our political culture: One side loves our military and lives alongside it; the other party respects — even reveres — our men and women in uniform. Yet reverence and respect are poor substitutes for kinship, as Jim Webb himself learned about a year ago.

In a speech announcing that he had ended his long-shot bid for the nomination, Mr. Webb wondered aloud whether his views were consistent with the “power structure and the nominating base of the Democratic Party.” Hundreds of thousands — possibly millions — of working-class whites switched their votes from Barack Obama to Donald Trump. I suspect many of them thought the same thing when they went to the polls.