It started with the post great recession, Occupy Wall Street movement. That was the first major populist movement in the US in the 21st century. Even though that largely failed to result in anything draconian (fortunately), the US banking system was brought under far stricter control. The Fed with the Treasury is capable of dictating almost everything about the businesses of the large financial institutions. Today the US financial system is by far the strongest and safest financial system of any major economy. It's due in part to that populist response after the crash.
Trump's election was in fact also a massive populist backlash, against electing more of the same political dynasties (Clinton / Bush) that had come to rule the US. Trump defeated powerful, massively well-funded representatives of both entrenched dynasties to win the Presidency (which tells you just how dramatically voters were willing to reject a continuation of the old). Trump is the first populist President that the US has had in a century. Nearly every organization and individual that was part of the entrenched establishment was against Trump and he won regardless. And no matter what people think of Trump, his election will represent a permanent split with the past when it comes to the US political system. Things will never be the same, to put it mildly. AOC, as one example, is in Congress solely due to this cultural shift, new outcomes are possible (variations of Democratic Socialists were exceptionally rare in the past; they won't be rare in the near future). Obama was also partially responsible for and representative of this process that is underway; it's no coincidence he won immediately following the great recession crash, as the backlash and desire for a different direction is part of what made him possible (Hillary Clinton or McCain win that election otherwise).