This book is about the political activities of Einstein. He is of course known for his scientific accomplishments, but spent much of his life pursuing political causes of various sorts. The causes were varied, rescuing Jews stuck in Nazi Germany, fighting Franco in Spain, fighting anti-immigrant prejudice, etc. His involvement with such causes put him in the company of some very radical people. At the same time, J. Edgar Hoover decided that Einstein was somehow an enemy of the US and started a file on him. This book is based on the contents of Hoover's file obtained from the FBI under the Freedom of Information Act.Around 1950, Hoover decided that he wanted to find a way to deport Einstein. He could not publicly harass Einstein because he was so well respected. Instead, he pursued false leads and obtained information from nefarious characters in an attempt to prove that Einstein was a communist. Proof of such a thing would have made it possible to deport. Such proof was never found. The investigation was finally ended in 1955 when Einstein died.Einstein was lucky and smart. His stature as a great scientist made him immune to the public attacks of people like Joe McCarthy and the HUAC. They would not have dared to force him into one of their hearing rooms to testify. Others around him were not so lucky. They were stripped of their dignities, livelihoods and sometimes even their lives by these small-minded bullies. Einstein spoke out forcefully against McCarthyism and used his relative immunity from attacks in a carefully measured but extremely effective way. This book should give pause to those who would revive the memory of Joe McCarthy and J. Edgar Hoover. Many nowadays are again starting to call them great Americans. Even greater are those such as Einstein who stand up to the abuse of power in a selfless and courageous way.