LOL. Some sort of typical Atlas question
Nothing is inevitable, especially not from four years from now. Anything can happen. A major scandal or economic recession and the incumbent president (no matter of what party) gets thrown out of office very fast. Examples: After winning a landslide after two term of GOP presidents, everyone was sure that Herbert Hoover wins reelection handily. Until the depression came. In 1948, Truman was expected to lose big ever since two years before the election. Also, in late 1982, it looked like Reagan is in big trouble, but he went on to win in a landslide. Poppy Bush was also seen in a strong position by late 1991. This year, Hillary was also seen as inevitable. So, the question is pure speculation/not to answer.