The Obama Democrats who gather in Charlotte this week have a big advantage over Tampa’s Romney Republicans: Last week’s GOP convention gave President Obama a peek at Mitt Romney’s playbook. Combining the lessons of this highly public briefing with what’s already known about the Romney strategy defines the Charlotte Imperative.

Several things are obvious. Romney has been stung by the attacks on his career at Bain Capital and knows he has a serious likability problem. That’s why so much time in Tampa was spent countering these liabilities. Democrats will continue to exploit them.

The Republican nominee also signaled that he intends to couple harsh assaults on Obama with a more in-sorrow-than-in-anger approach aimed at voters who still like the president but are disappointed he didn’t live up to their hopes. The best lines in both Romney’s and Paul Ryan’s speeches spoke to the disenchanted. Obama will have to speak directly to them, too: explaining why the economy isn’t where it should be, arguing that his path forward is still more promising than Romney’s, and linking his second term plans with the hopes of 2008. These goals lie behind Obama’s “Forward” slogan.

Even conservatives have conceded that Romney left a huge opening by doing little to specify what he would do in office. Obama will define the Romney agenda himself, but he’ll also have to offer his own plans as a contrast to Romney’s vagueness. Since Romney accused Obama of “divisiveness,” Obama will have to explain why the division in the country was caused primarily by the GOP. He’ll be helped in this by the behavior of Republicans in Congress — they’ll be star players in Charlotte rhetoric — and by the caustic character of so many Tampa speeches.