"McCain, on the other hand, has a long history of bipartisan cooperation. He has "walked the walk" not just "talked the talk". He is, without doubt, the most visible member of Congress who is truely willing to work accross the isle."

A decade or more ago, yes. In the past 8 years, not so much. McCain has pretty much voted in lock step with the Republicans and Dubya in recent years. He has neither been much of a "maverick" nor a bipartisan "unifier."