The economy under Obama, at least the last three years of his administration, was a 2.0 percent growth rate. It had the liberal economists saying, that was the limit for the economy. Trump blew past that, not quite 3 but close, and drove down unemployment to record (1994 onward for recording) of black and latino employment.
A year, maybe two, goes to the previous administration, say Clinton in ’93 and ’94 went to Bush, who put everything in place, but it came a bit to slow to re-elect him. Last year, if not the year before, goes strictly to Trump. At some point the present administration owns the economy, the previous one can no longer be blamed.
If recent polls are to be believed 20+ percent of Blacks will vote for Trump. 20+ percent of Bernie voters, will either vote for Trump, third party, or not vote. 30+ percent of Hispanics will vote for Trump. That plus the working class gives him the election at this point.
Everything hinges for him on how the economy both opens up and starts getting jobs back. If he is just reasonably successful, he win,if not, he loses.