California Governor Jerry Brown will be speaking tonight at the Democratic National Convention on climate change. Vice President Joe Biden will speak. And President Barack Obama will deliver what is being called an optimistic 30-minute address that was a month and six drafts in the making. Among other things, he will say, according to excerpts obtained by CNN: "As I've traveled this country, through all 50 states; as I've rejoiced with you and mourned with you, what I've also seen, more than anything, is what is right with America," he will say.