One-termer
Anyone elected to office who, after demonstrating clearly that their election was a mistake, faces the prospect of defeat in the next vote in spite of the generally recognized power of the incumbency.
Now that Donald Trump has alienated all but the most radical elements of his base, it is likely he will be a Presidential one-termer.
one-termer
a person who rises to the highest level of political or other office for only one term or round
I can't believe Joe only managed to be president for one round of asshole after he played for 3 hours ... he's a one-termer