Incumbents almost always win their elections. Who knows where we'll be in 4 years, but in general, an assumption that a new President-elect will serve two terms is reasonably safe.
Ok, so I'd never actually tallied the numbers. This does indeed indicate that Trump has a roughly 6/10 prior chance of winning reelection.
Mind, I think that prior is moved by the fact that he's a historically unpopular president-elect already, but we will indeed see over four years what he manages to make of himself. Or whether he manages to collapse capitalism once and for all.
You have to consider the circumstances around the incumbents that failed to be re-elected. Ford lost the election because of his association with Watergate and particularly his decision to pardon Nixon. Carter lost primarily due to the failure of Operation Eagle Claw. George H.W. Bush lost because Perot came in and split the conservative vote.
Stretching back further in the 20th century, Hoover lost due to the depression and LBJ declined to run for a second term because the Vietnam War was so unpopular they knew he wouldn't have a chance.
None of those are conventional political circumstances. So while you're right that it's about 3/4 incumbent races won, it seems that if there isn't a massive ongoing crisis, scandal, or political anomaly, the incumbent's chances are very good.
"In reality," says mathematician John Allen Paulos, "the most astonishingly incredible coincidence imaginable would be the complete absence of all coincidences."
For a job like president, the circumstances are almost always ongoing a crisis or political anomaly. I imagine re-elected incumbents also had to face exceptional political circumstances, just were able to navigate through them with luck and skill.
...and really, in general this is just so much post-facto justification. Whatever the election result, Reasons will always be found in hindsight. If Clinton had lost in '96, you'd be able to say it was due to the Whitewater affair. If GWB had lost in '04, you'd be able to blame the unpopular wars in the middle east (or more specifically, Abu Graib). If Obama had lost in '12, it would be easy to pin it on Obamacare.
reply