I like to remind myself that very few people reach positions of great power after mediocre lives. Rather there’s a thread of talent that runs through government.
Once they’re in, the predilections that led to power often rear their dark long tails. But they’re all (even the ones I disagree with) talented.
Politics is fundamentally the art of convincing people of things - usually “vote for me.” That is the only skill that acquisition of high office is evidence of. Many politicians have more skills than just than that, but the mere fact of having acquired high office tells you nothing more about a person than that they’re particularly good at politics.