We may not know who our next president is going to be, but here’s one thing that’s almost certain: he or she will take office with roughly half of the electorate unhappy and mistrustful. The notion that the president speaks for a broad coalition of Americans who are willing to set aside their differences on behalf of a compelling new vision for the country? It’s vanished.

I’ve spent a lot of time pondering where it went, and though I still haven’t found an answer, I do know this: it’s not only Washington’s — or even the political class’s — fault.

Let’s start with a lament I hear frequently about this year’s crop of presidential candidates: “Is this the best we can do?” I used to believe that the popular argument that the best among us do not seek political office was wrong — that there were plenty of standout Americans who went into politics. And there are. But there are also a lot of talented people — the kind who could lead us beyond our tired political discourse — who take a look at politics and turn the other way these days.

I’ve known a lot of good people in politics, who were motivated by a true interest in improving the country and saw politics as a competition of ideas, not a mean-spirited clash of ideologies. I see less of this today. Many politicians seem genuinely not to like one another. They see a victory by the other party as a threat to the well-being of the nation.

This is a departure from the past, and it’s not a healthy one. There was a time when the parties and other organizations that brought disparate voters together — charitable institutions, unions — helped build a unity of effort in the government. But groups like that are weaker now.

Which is a shame in a year like this, when voters are angry and distrustful and worried by economic insecurity. They don’t have much appetite for the substance and complexity of policy, seem to relish the clashes that this year’s campaigning has produced, and are uninterested in talk of finding common ground.

It’s a campaign year, of course, so a certain amount of this is to be expected. But if the voters’ surly mood and mistrust carry over after November, it’s going to be very hard for the next president — and politicians in general — to govern effectively.