This came out in 1968 in response to China's leader Mao's little red book. In this book on LBJ it takes speeches, comments, observations, and off the cuff statements that were often taken out of context and put into one very 1960's volume.
The 1960's were all about anti establishment and this is a bit of that.
In 1968 it was expected that Johnson would run again for office. However, as I recall watching on TV he announced he would not run. That made this book a bit a bit of a useless thing. But when it came out it had its followers and collectors. None more so than members of LBJ's administration who wanted to know what the Hell was in it.