A field of knowledge consists of many accurate, well understood ideas within that area. If a ten-year-old memorized an accurate article about astronomy, she would not be knowledgeable in that field because knowledge requires a huge number of accurate, well-understood ideas.
Trump gets criticized for not knowing politics and policy issues. And they're right.
The problem is that almost all other ruling group Western politicians have similar flaws. Their knowledge consists of how to screw people over, call it the political SPO field. These politicians have little knowledge of logic, ethics, and policy reforms. If you asked most ruling group politicians what Pigouvian taxes we should enact, their answers wouldn't be close to right, many wouldn't know the meaning of the word Pigouvian.
Ruling group politicians know thousands of leaders, lobbyists, diplomats, and advisors. They memorized thousands of talking points. But the talking points are either fallacious or intended as bait-and-switch morsels. They have political SPO knowledge, but not ethical and policy knowledge. Politicians are altruistic toward their friends and relatives, at the expense of the people. But since they are devoted to egoism, politicians easily believe helping allies is the same as doing their duties for the people.
Most people become national politicians because they want more power, status, and money, no matter what they claim their ethical motives are. In evolutionary terms, this is called psychological egoism.
Trump also has SPO knowledge from business fields, note his ability to have his corporations file for bankruptcy without his own wealth being destroyed. Trump's egoism is well documented.
That's why a random person walking down the street would likely be a better president than most billionaires or national politicians. The random person is less likely to be devoted to egoism. The professional politician will parrot or come up with all sorts of SPO schemes and fallacious rhetoric to support the schemes. Often Congressional bills will be written by lobbyists.
The random person turned politician might just say no to many such schemes, realizing what is at work.
We are now subjected to a plethora of poorly reasoned "As a lifelong Republican..." articles warning us about Trump, the fake centrism on full display. Being a lifelong Green, Republican, Democrat or Libertarian does not make one an expert. If anything, it makes one guilty. These authors would rather vote for a totalitarianism that starts a super war with China or Russia than anyone who opposes the invasion and annihilation of the West by migrants. These lifelong articles contrast Trump with the disastrous presidency of Reagan. The authors assume readers will be unaware of Reagan's real record, the over 30 percent decline of median incomes in young families with children during the 1980s, despite massive increases in wives working. Instead, the fairy tale emphasizes winning the Cold War and the Reagan boom, nevermind that the West lost the Cold War and boom was only for the wealthy.
You might as well vote for yourself rather than anyone the ruling group political parties offer.