Um...did you just miss what happened in Mixhigan 2018? If Detroit votes he will lose. If Milwaukee votes he will lose. Same for Pennsylvania.
Probably, but those are some pretty big "ifs". I'm sure at least some of the Dem base will be unhappy with whoever wins the primary and stay home. Not to mention voter suppression and shyt.
After 2016 I refuse to give anybody the benefit of the doubt.
80% is too high. It's 51-49 IMO. He's the incumbent but he hasn't expanded his base. He's polarizing. He's not particularly popular.
Like @No1 said, its not like he dominated in 2016 to win. It's less than 80,000 votes in 3 states. The Dems did better in 2018 in those states. Trump isn't overly popular in the Midwest. If he had an approval ratings in the mid 50s, then yes, I'd say he has a 60-65% chance of winning. But he's routinely around 40% and on high end at 45%.
Obama was around 52% approval on election day 2012.
Republicans have an electoral advantage, they don't have to be as popular as a Dem has to be to win. Unfair but true.
Trump's approval rating now is about the same as it was when he got elected. Dems can win but only if people who didn't vote in 2016 show up in large numbers. Trump having a mediocre approval rating isn't enough.
There's also what I'd call the "Gillum Effect", ie. people who are going to vote for Trump but don't admit it to pollsters for whatever reason.