Medieval politics was personal and individual. I understand "Game of Thrones" captured that well. We think of that as petty and selfish - a king is supposed to act for the good of his people, not only for his and his family's own advantage. That a duke slighted you is not now considered sufficient reason for war. It was then. In fact, it has been the norm for most of human history, and the medieval era could fairly be considered one that moved us in the direction of rulers having more concern for the ruled. Henry IV was a pretty good king, but didn't get much credit for it in his day. People didn't like him much.
We owe a great deal to George Washington's example of being a president of all the people, and being above party. The presidents who succeeded him had been generally vicious partisans on their way up to the office, but the first few, who had seen the value of Washington's political neutrality, tried hard to match it. They considered it "befitting to the office," and it set the tone for those after. Today we consider it automatic that presidents don't take us to war over personal issues. It was one of the things some worried about with Donald Trump, that his vindictive responses to internal political conflicts would be echoed in international affairs, and he would take us to war with a country whose leader had crossed him. That has not proved to be the case. In fact, one could make a fairer case against Obama and Bush 43 letting personal opinions of other rulers or nations cloud their judgement. I haven't thought it through beyond that. DJT might score above many others on that scale. Even if he's dead wrong in his decisions, I don't think it can be said that they reflect personal scores to settle, or being blinded by guys he just likes.
I don't think we are very far above the medievals in this attitude. We are mostly just pretending we have reasons why we like political candidates. We look in irritation at the consultants who try to sell their candidates on the basis of image rather than ideas, but they likely know better than we do that the ones who disapprove most are equally susceptible to being manipulated. I have a friend of good, longstanding conservative credentials who keeps telling me how upset he is with Trump. He's not a good family man. Can you imagine what it must be like to be in that family? He didn't vote for Obama either time, but he admires what a good family man he was. (I only partially grant that, BTW. Yet I at least take his point.) I tell him I would much prefer Trump be a better husband and family man, but it ultimately doesn't affect my vote. My friend reluctantly agrees, but then two weeks later he tells me how Trump's bragging bothers him. It bothers me, too, but it is well down the list of what I'm going to vote on. My friend just doesn't like him, and the issues take a back seat. He's not the only one I know.
It is the same on the other side of the divide. I briefly shared an office with someone who is radical enough left that he hasn't much liked most liberals until Bernie, and now this crop of farther-left Democrats. He does agree with radical conservatives at least partly on some issues. In our conversation I said "One of the things I was worried about with Trump was that he was going to impulsively and vindictively get us into war. If anything, the opposite has been true." He paused, caught my point, and acknowledged that he could at least see why I thought that was a reason to support him. Yet he quickly went into other criticisms that were not entirely issue-based, and one of the women at the table shivered about what a horrible man he is and women have every right to be worried about what might happen to them. I pointed out that John Edwards and Bill Clinton were worse, and nothing bad seems to have happened to women under Trump, but the reply was a shaking of the head and another shiver. They just don't like him. The issues don't matter.
It is similar on the other, other side, of those who support him. I comment on a half-dozen conservative sites, and at each there are regulars who will not only defend Trump no matter what he does, but call you names quickly if you disagree with him about anything. Tariffs are a bad idea. Maybe Trump can wrest a short-term tactical victory from the use of them, but they are still a long-term loser. Because much of what is lost is opportunity cost and creative destruction we don't see the price tag, but it's still there. Even if the trade war with China hurts them more than us, it still hurts us, and some sectors more than others. It's a real cost that some neighbors are paying, even if it works out for our long-term benefit. But if anyone says that, they are dismissed as elites or neverTrumpers, who just don't see that he's playing 3D chess and outwitting them all. They just like him. They repeatedly praise him because he fights, as if that were somehow the key. He kicks the people they want to see kicked, and they just like him. They insist that the constant insult and combativeness are an essential part of the strategy.
Well tell that to Bill Belichick. (Who I think would be a really fun president to have, BTW.) You don't actually have to say "Screw you, I'm doing it my way," you just have to be unaffected by what stupid or untrustworthy people say. That's the part Trump gets right, being unaffected and doing it his way anyway. The combativeness is part of the package with him, and perhaps was necessary to get elected in the current climate, but it's not necessary to governance. Plenty of great leaders have done without it. Washington dealt with armed rebellion and threats of secession. Lincoln had a full-fledged civil war. Yet kicking is the part some Trump fans like. They believe that combativeness, rather than confident independence, is what has been missing in the past. They say that he and his abrasiveness are what is doing it all, with no help from the Republican establishment. You tell me how successful he would be if the Senate was 70-30 in favor of Democrats. No Federalist Society recommended judges appointed at multiple levels then.
DJT has been successful at the tipping point for the Republicans and that is valuable. Not everyone can do it. Yet the scales have to be closely balanced for the tipping to even be a possibility.
Obama infuriatingly said "You didn't build that," when the people he was speaking about absolutely had built that. Government can provide value-added or value destruction, and that can indeed be crucial. There are plenty of places with ruined economies because their governments didn't do its job well. But the government didn't build that, the people operating in a free market did. So too with Trump - and to be fair to him, for all his braggadocio, he is not the one claiming he's doing it all, it's his die-hard fans - he didn't build that. The hated Republican establishment built that, but proved repeatedly they could close the deal. He has provided value-added, and it has been crucial WRT judges. He has been helpful in terms of the economy, but he'd be the first to tell you that it is millions of people working at their jobs that is building that. At the moment, his foreign-policy choices look okay among the usual list of terrible choices leaders have in this fallen world. In all these things, it's not a fair world. Some presidents can get away with numerous bad decisions, so long as they don't get them all wrong, because the times are not critical. Others need to get 80% of their decisions right or they fail, because the times are dire.
But sometimes people just like him, and they are going to support him even when he goes against their previous ideas.