Some possible other wordings (I can't really say corrections, because I don't always know what is wrong).

However, it eventually reversed its role, to become a dominating card.

The French revolution caused the ace to become more highly valued - it started symbolising superiority of ordinary people over kings.

In his later years Ernest Hemingway was very depressed and irritable, telling his family and friends that he was [haunted = followed = under surveillance] by the FBI everywhere.

A few times he was treated in a psychiatric clinic whence he called friends saying that listening devices were set in his chamber and his conversations were monitored.

Being under the influence of electro-shock therapy, he lost his ability to write and formulate thoughts as he could do previously.

The answer was: extensive surveillance had occurred, including at that clinic, because authorities had deemed his activity in Cuba suspicious.