The Pew Research Center did a study of partisanship study-news flash it is worse than ever! The study was done in April 2016 and does not include anything about Trump.
Now that the old news is out of the way, they published an interesting graph of popularity of the Presidents going back to Eisenhower.
The graph surprised me in showing a sharp difference among the Presidents. See figure titled: Six decades of Presidential Approval…
Four Presidents stood out by having maintained popularity among members of their own party (and often the other party-though at sharply lower rates) over their entire time in office:
Eisenhower, Reagan, Clinton, and Obama.
All the other Presidents suffered sharp losses of popularity toward the end of their time in office even among members of their own party.
It seems that this helps answer a recurring question here on the Straight Dope-who were the great (or at least good) Presidents? If a President can finish their time still popular with at least members of their own Party, that is some indication that they were successful.
I would speculate that it might be mostly about the timing of the economic cycle.
The economy goes up and the economy goes down, but if it happens to tank at the exact time that there’s a presidential campaign going on when the public is most focused on your presidency, then your popularity will tank along with it.
GWHB certainly suffered from that. When the 1991 recession hit, he was the biggest victim.
You may be right when the very periodic presidential cycle gets in phase with the aperiodic economic cycle, Presidents look gook. When anti-phase, they don’t.