Sadly, I see a non zero chance of Trump getting another 4 years.
On one hand he barely won thanks to our Electoral College and 70,000 votes across 3 states that put him in the office. It would be very easy to swing those states the other way.
On the other hand, if Mueller investigation comes up short and the economy keeps going as it is now for the next 2 years, I can see a lot of folks not wanting to rock the boat and voting for their wallets everything else be damned. These middle ground folks along with his base could theoretically put him in the office again.