As Bernie Sanders says often on Fridays on Thom Hartmann's show, the Democratic Party is a centrist party. It's progressive challenges from people like Nader that will be part of changing this, and reflecting more of the liberal base of the party... As long as Nader doesn't turn a swing state for the Republicans, his run will be good for the issues he raises. Moreover, the Dems should take note of the people who vote for the progressive principles that Nader uncompromisingly stands for.
Benjamin Franklin said, "Those who would sacrifice liberty for security deserve neither." What's more American than civil liberties? Which Bush has attacked with the 'Patriot' Act, violating the FISA law, and with the general mood of fear he has fostered in the country... Instead of doing what a real patriot would, and defending our way of life in the face of threats.
Obama has continually voted to fund the war. So I don't think his stance against the war prior to being in the U.S. Senate means that much. I'm not sure why more Democrats haven't voted against funding the war, the majority of the American people are with this position. For a politician to say s/he wants withdrawal, while voting to fund the occupation, is a contradiction... This does not represent a true anti-war view.