The Dead Zone: Stephen King

I like King's books that could be "possible" and this was one of those. The protagonist, Johnny Smith falls as a child when skating and gets a concussion. He starts talking nonsense about battery acid and then snaps out of his daze and seems fine. Shortly after the incident the man who helped Johnny has an accident when working on his car and the battery acid severely burns him. Johnny forgets about the incident and becomes a high school teacher. He takes his girlfriend to the fair one night and is mesmerized by the "wheel of fortune" He wins over $500 before his girlfriend, Sarah, gets sick and he takes her home. He was going to spend the night at her house but since she is sick he takes a cab, which is in a head on accident due to some children drag racing. Johnny spends the next 5 years in a coma and Sarah marries someone else. Johnny finally wakes up to find the world around him changed. He undergoes many surgeries to lengthen his atrophied muscles and realizes he has premonitions after touching people. He is able to tell his doctor that his mother is still alive and lives in California, he also tells the nurse her house is on fire. To Johnny's horror he gets media publicity and it takes a while for his life to settle down. He is contacted by a local sheriff to help solve a murderer and the town was surprised by who it was. Johnny follow the life of politician Greg Stillson and eventually meets him and shakes his hand. In that shake he learns the horrible war Stillson will start and becomes obsessed with determining what he should do with the information he learns. He asks people if they could go back in time and kill Hitler, would they?...most say yes. Johnny learns he has a brain tumor and decides to forgo treatment and to assassinate Stillson. Johnny is a bad shooter and misses Stillson, but watches the future change anyway before he is shot to death by Stillson's bodyguards. Stillson grabs a woman's baby and uses it as a shield while trying to get to safety. A man gets a picture of the incident and then people are outraged at Stillson, who never becomes president.