The Dead Zone (Signet)

Waking up from a five-year coma after a car accident, former schoolteacher Johnny Smith discovers that he can see people's futures and pasts when he touches them. Many consider his talent a gift; Johnny feels cursed. His fiance married another man during his coma and people clamor for him to solve their problems. When Johnny has a disturbing vision after he shakes the hand of an ambitious and amoral politician, he must decide if he should take drastic action to change the future. ([source][1])

[1]: www.stephenking.com/library/novel/dead_zone_the.html