I agree with most of that, but there is a huge disconnect between the economy and Trump's overall job approval. RCP puts Trump's approval on the economy at 52.3%.
RealClearPolitics - Election Other - President Trump Job Approval - Economy
But Trump's overall job approval at 42.6%.
RealClearPolitics - Election Other - President Trump Job Approval
I've never seen that huge of a disparity. Usually if the economy is going good, a president's, any president job approval is at 50% or above. You can go back with any president when economic good times and find his overall job approval 50, 55 or even above 60%. When the economy sours, any president's overall job approval falls below 50%, sometimes into the 30%.
Presidential Job Approval Center
Reagan fell from a high of 67% overall job approval down to 35% when the economy didn't improve and had a horrible first midterm due to the bad economy. But over the next two years economy improved and Reagan shot up to 62% job approval and easily won reelection. One can say how folks viewed Ronnie was economic among other things. Trump has had a very good economy and has to yet reach 45% overall job approval. Something else is at work with Trump.
Obama had a 53% overall job approval in 2012 and won reelection.
G.W. Bush was at 55% he won reelection
Bill Clinton 58% he won reelection
G.H.W. Bush was at 40% over all job approval, he lost reelection
Reagan as I stated was at 62%
Carter was at 34% overall job approval and lost.
Ford at 45% job approval, lost.
And so on. Like with the economy you cited, one can relate that a president who's overall job approval is below 50% loses reelection, above 50% wins. With a 10 point difference between the economy and over all Job performance or approval, there's something else at work here. Something else comes into play.
I've always held it was his persona, his obnoxious personality, his unpresidential behavior. Trump is a very easy man to dislike because of that. I may be wrong, but I think it is Trump's character and behavior as president, his as seen by many independents, uncouth personality that has caused many independents to desert him. Not the economy or even Trump's stances on the issues and policy. But the man's persona. Time will tell.