I don't think it's as simple as saying that he'd just get **** because he's Trump. You yourself acknowledge the myriad of ways in which our cultures impact our perceptions and cognitions. With any issue, there's always a plethora of evidence for and against numerous issues, but our mind tends to filter things in and out to make what we're seeing more consistent with our underlying worldview and biases. I acknowledged this recently with regard to Cuomo, stating that there's a lot of nuance regarding his failures. And, honestly, the actual data behind it is truly awful. Despite that, I've weighed in with my experience on why simply criticizing him off the (admittedly awful -- an understatement) data regarding COVID is too simplistic. But people on the right are happy to highlight this. Perhaps even many people not politically inclined. But it neglects a number of very relevant issues. But on the left he's viewed very favorably. To suggest that this is the case purely because of the data is not a position that can be supported in any iota. So people are mostly coming to these conclusions (whichever side of the line they fall on) based on pre-existing notions that are influenced strongly, among other things, by politics and media. Regarding the First Step Act, you can point to no criticism, but was there much praise? I think it was ignored, mostly. COVID is a lot harder to ignore, as it's currently impacting all of our lives, and has so for the past 4 months, so there's no choice for anyone to ignore that. I think the idea that "had Trump done ______" means this would have never gone political is being fairly generous. And I think it's hard to argue that I possess such a belief out of political convenience, as I have no history of crucifying any political leaders on the other side of the aisle, and my most recent example has me (sort of) providing a level of defense for a known Democratic politician. But there's a lot of data on COVID, and lots of good (meaning positive data) but it gets no traction. I don't have any doubt that the amount of discussion those favorable things would get would change to a pretty reasonable degree if we were to change a couple variables in this equation. Unless, of course, you believe the country's collective values are completely independent of any potential biases. In that case we are a much more pure and altruistic society than you have previously argued.It's a little sad top see you trying to argue that, if your guy had done the right thing, everyone would be for doing the wrong thing. When Trump signed the First Step Act, there was no significant criticism from the left (except for it perhaps not going far enough). They haven't been hounding him to be more aggressive in foreign military matters. If Trump had gotten ahead of the curve, he would have been vindicated instead of reviled.
Very few people are reflexively opposing Trump. It just seems that way because he is so very often wrong.