Story : As Johnson's term of office drew to a close, riots raged in the inner cities, and anti-Vietnam protesters demonstrated all over the country. With the United States as close to anarchy as at any time since the Civil War, Johnson felt he was living in a continuous nightmare. The final programme reveals how those who knew him best still regard him as a great man who almost realised an impossible dream. What he wanted was time to build his 'Great Society' - but time was running out. Part 4 of 4.