Regime Change: Inside the Imperial Presidency of Donald TrumpMaggie Haberman and Jonathan Swan, Simon & Schuster, £28“MEN are more ready to repay an injury than a benefit,” wrote Tacitus, “because gratitude is a burden and revenge a pleasure.”These words by the great Roman historian, who lived the tyranny of several mad emperors, comprise a lesson about the nature of power, and unwittingly foresee the fate of the United States.