Over all, the message will be of Mr. Obama as “someone who kept the economy from falling into a depression, who is fighting for the middle class every day and understands where the economy needs to be not just next month and next year, but for the long term so that we can compete with China and India for the future,” said Dan Pfeiffer, the White House communications director…

At the same time, Mr. Obama is expected to begin a nationwide effort to warn the country of what Republican leadership, in his view, looks like, Democratic advisers say. That means the president will single out Florida, Ohio and Wisconsin — three states where Republican governors clashed with civil servants, for instance — as a warning of what could happen if a Republican takes the White House. (“Get those nurses and firefighters who lost their job on television,” one Democratic adviser said.)

In those three states and others, like Pennsylvania, where a disproportionate number of voters are older, Mr. Obama will hold his Republican rival responsible for proposals to replace Medicare with a smaller voucher system and to make Medicaid a limited block grant to the states.