Excerpt: RAY SUAREZ: It was former Speaker of the House Tip O'Neil who called Social Security 'the third rail of American politics' because it meant certain death to any politician who touched it. But during the election campaign, President Bush vowed to do just that in his second term, arguing now was the time to reform the Social Security system before it became insolvent. Today the president repeated that pledge, and laid out some principles, during day two of his economic summit.