I've thought this for awhile. I call his win the miracle of Trump. Not because I think he's great, but because he was the only one in that big Republican primary field who showed that he was capable of cutting through the headwinds of being an outsider. That said, I never thought he'd win it all.
Even after he did win, I thought his Democratic roots would bob up to the surface, and that he was going to revert to moderate policies. But I believe that his conservatism may be a reaction to the way he's been treated by the Left and his own never-Trumpers ever since Election Day, 2016. I'm stunned that he's accomplished all that he has. I tend to agree with Plenzmd that "winning ugly" is better suited for my sports teams than for my President.
If his policies remain after he's gone, I'm good with that -- because he didn't just stop the march of progressives, he turned that course around completely. I love the fact that he fights back against the BS hurled at him, and if that legacy continues with whomever his successor may be, I'm good with that. But I hope to never see his particular demeanor replicated by another President.