The USA became this through Trump being elected.
I think Trump being elected is a result of anti-thought, feudalism-seeking part of society coming to power, not a cause. Enough people were fed up with thinking elites stealing from them, so they elected thought-averse elites to steal from them because they naively thought that the stealing is because of intelligence.
What? Trump is just a symptom. The US didn't suddenly become what it is now because of a vote. Like it or not (and I certainly don't), the people voted for this, twice. Whether they voted for it because they actually wanted it vs they voted for it because politicians convinced them they wanted it, it is what we wanted.
It started with Richard Nixon and his cynical manoevering.
It was reinforced with Ronald Reagan. Remember how he spun the Iranian revolution and the bad economy on his opposition? Remember how he rode the Moral Majority wave?
It was taken up a notch by G. W. Bush and his band of trigger-happy self-serving country club elitists.
No one in between those points tried to roll back the progress. They're just as guilty. It's been a monotonic increasing function towards the current apex (nadir?).
Fear what comes next. If there is a next.