We campaign in poetry, Mario Cuomo used to say, but we govern in prose.

That was how the then-New York governor explained the gap between his soaring speeches and the more prosaic product of his government, when the springtime of campaign hopes succumbed to the winter of governing discontent.

That was a generation ago. But it is a pithy summary of Barack Obama’s challenge as he goes before his convention this week.

There are a lot of very angry people in the country, out of work or living on less. But anger is not the dominant political sentiment among the voters likely to swing this presidential election.

“There’s absolutely a sense of disappointment among a large subset of Democrats,” said David Segal, a former Rhode Island state legislator who now runs an organization that lobbies for Internet freedom and civil liberties.

The Romney-Ryan team astutely recognized the discontent and tried to package the sentiment at the Republican convention last week. The purpose was to peel away voters who were proud of their vote for Obama four years ago and are disappointed now by the state of the country he has been leading ever since.

“The president hasn’t disappointed you because he wanted to,” Romney said in his acceptance speech. “The president has disappointed America because he hasn’t led America in the right direction.”

Michael Oreskes