BURLINGTON, Vt., Aug. 14 - “We are now in the midst of the fiercest and best-financed attack against Social Security in our lifetimes,” Sen. Bernie Sanders (I-Vt.) warned today on the 77th anniversary of the most successful program in the modern history of the United States. “Hundreds of millions of dollars are now being spent to destroy Social Security and endanger the well-being of millions of Americans. We must not allow that effort to succeed.”