(FORTUNE Magazine) – Republicans may have the economy humming, but much of the electorate seems not to be listening. Despite low inflation and low unemployment, national polls reveal that voters are worried. In July the Chicago Tribune found that 58% of those surveyed in five of the largest states disagreed with the statement ''The economy has been good under the Republicans and there's no reason to change.'' The figure was 53% in a similar poll last November. As the Democrats headed home from the Atlanta convention, they were preparing to use that anxiety on the electorate. They can start with middle managers. In recent months Barry Stein, president of Goodmeasure Inc., a Cambridge, Massachusetts, consulting firm, has spoken to hundreds of managers, many worried about losing their jobs. Says he: ''They feel they don't matter to their companies like they used to, and they aren't hearing sweet music from Washington.''