President Obama's 2008 campaign manager wants Democrats to start focusing on defining their Republican opponents.

David Plouffe, who recently took on an expanded role advising the White House on 2010 elections, told the Washington Post that Democrats haven't sufficiently defined their GOP counterparts as obstructionists.

"Republicans right now are just sitting back and slinging arrows," Plouffe told Chris Cillizza. "We need to infiltrate their camp and shine some light over their side of the fence."

More from the interview:

"Politics is a comparative exercise," Plouffe, who managed Barack Obama's presidential campaign, told the Fix in his first extended interview since he took on a broadened political role for the White House in advance of the midterm elections. "This isn't just a referendum on Democrats or our party. It's a choice."

That choice was made explicit far too late in last month's special Senate election in Massachusetts between then-state Sen. Scott Brown (R) and state Attorney General Martha Coakley (D), Plouffe noted. "Everyone would agree that the definition of Brown should have happened a lot sooner and a lot more clearly," he said.