Positioning is complicated. You have to take into consideration the shape of the ground and the positions of others: who is at your side, who is above you, behind you and so on. Without studying Sun Tzu's strategy, very few people have a sense for what is involved. As someone who should know Sun Tzu's strategy, McCain should be concerned about moving so far to the center that he leaves his flank to the right exposed. This problem is highlighted by Bob Barr joining the race on the Libertarian right. This is important because third parties, winning small percentages of popular votes have had a outsizes impact on recent elections. In 2000, Ralph Naderâ€™s 96,000 votes in Florida tipped the balance to elect George W. Bush as president. In 1992, Perotâ€™s Reform Party won almost 19% of the votes tipping the election to Clinton and defeating the first president Bush. Nader, of course, is back, but looking at their strategic positions in the race, the danger to McCain is much greater from the Libertarians on his right than the danger to Obama from Nader on his left. McCain, of course, isn't helping the problem by running to the center (some would say the left) on issues such as global warming and immigration. Considering the fractures in the Democratic Party, McCain should probably be more concerned about protecting his flank than outmaneuvering his Democratic opponents.