The former New Mexico governor said on CBS' "Face the Nation" Sunday the convention would be a stark contrast to the recent Republican event and would inspire the same enthusiasm that swept Obama into office in 2008.
"My sense is that that coalition that elected the president, the young, minorities, independent voters, is going to be there," Richardson said. "I think there's a view that the president is moving very much in the right direction, that the second term is going to show him, I think, go from a good president to a great president."
Richardson said the 2008 campaign drew strength from the idea of national unity and economic progress for all. He said the Republican convention stressed an us-against-them theme that would not appeal to centrist voters.
"You're going to see a real effort to engage the middle class, engage the American worker, and say that we want to be positive about this country," Richardson said. "We're not going to be a bunch of negativists."
Richardson said actor Clint Eastwood's appearance at the convention was more than a novelty. He said it sent a clear and divisive "lonely gunfighter" message to the nation.
"I think the Democratic Party is about family, about unity, about bringing people together," Richardson said. "We're all in this together. We're all trying to rebuild the economy together."