Whitehouse: GOP 'can't tell a positive story'

During an interview a few minutes ago with US Senator Sheldon Whitehouse for a forthcoming story, I asked him what advice he would give to Barack Obama, given how the aforementioned Rasmussen poll shows a dead heat in the presidential race. Here's what he said.
I think he needs to continue to broadcast his message for change. I think he needs to develop the field campaigns, the local organizations that were so effective for him in the primary. And I think he needs to be prepared to be more aggressive with Senator McCain now that his campaign has chosen to go a bit into the gutter with advertisements that [some] newspapers have described as outright false. [We] can’t let him get away with that stuff.
Whitehouse was asked about his level of concern about the effectiveness of the Republican attacks.
I think it’s something that we’ve got to be prepared to address. [Candidates use negative advertising because it works]. Given the policy familiars, they’ve got no place to go to a tell a positive story. All that’s really left is to try to try to scare people about terrorism and to try to smear the Democratic candidate.