There have been a number of questions of the form "what kind of president X will be [has been]: great, good, average, poor, or terrible." I calculated a net score for Donald Trump, with great +2, good +1..... terrible -2."
The first time it was asked was in April 2011, when there was some talk of him running for president; the second was in January 2016, when he was a contender but not yet the clear favorite. It was asked again in March, August, and October 2016, when he was the favorite and then the Republican nominee. Then there was one in December 2012, after he was elected but before he took office, another in June 2020, and two in early 2021 (Jan/Feb and March). Finally, there were two during the 2024 campaign. Basically, there seems to have been a drop as people got to know him during the 2016 campaign, but a pretty steady rise after that point. January 6 doesn't seem to have hurt him--his score in late January/early February 2021 was a little higher than it had been in June 2020. But then there is the exceptionally favorable assessment in December 2020--still more negative than positive, but only slightly. What explains it?
Here is the percent saying that he will be (or was) a great president:
That's a pretty steady increase as he solidified his position among Republicans (although it's worth noting that his highest figure is still below the 23% who rated Barack Obama as great in December 2016).
Here, the December 2016 survey stands out, with an unusually low number saying that he would be terrible. Apart from that, it didn't vary much between 2016 and 2024.
I think that the drop in "terrible" ratings in December 2016 reflects "diffuse support" for the political process: people were willing to put their doubts aside and give the newly elected president a chance. Unfortunately no parallel question was asked for Biden immediately after his election in 2020. Hopefully it will be asked again for Trump in the next month or so. I would guess that the effect has weakened or disappeared, partly because people know him better, and partly because general support for the process has become weaker: that is, the share who expect him to be terrible would be about the same as during the campaign.
[Data from the Roper Center for Public Opinion Research]