I don't think so - if the Republicans nominate someone like Ryan or Haley, Clinton could lose. Especially if there's a recession before 2020 (and there very well may be).
Agreed,
If d a recession happens combined foreign policy problems and the inevitable Clinton corruption occur on her watch then it's very possible she'll lose.
Besides we are way overdue for a 1 termer anyways. Hillary also wouldn't be winning this year if the GOP had actually nominated a coherent sane candidate anyways.
Then again in 2020 if she faces someone in the mold of CHUMP or Cruz she'll prob win again.