The public has moved more left for good reason. Things like canceling student debt, police/prison reform, homes for the homeless, ubi, being more open and supportive of the lgbt etc. And the government moved more to the right. Pretty obvious observation imo.
Under a Democratic President, student debt has not been cancelled. Criminal justice reform negotiations on the federal level ended with no action taken while some municipalities have enacted police reform and others have increased law enforcement budgets. Despite the value experienced of sending checks to people during the pandemic, there has been no movement on a universal basic income and there still is no federal law against discrimination against sexual minorities (or "LGBTAIA+, if you prefer).,
Nor has the federal minimum wage been increased and reproductive freedom, wiped out in some states and hanging by a thread in some others, is likely to be eviscerated soon by the US Supreme Court. The Overton Window has moved right and Ocasio-Cortez has noticed:
Billionaires be like “the extreme far left is taking over” when the “extreme far left” in the US is “medicine shouldn’t bankrupt you,” “wages should cover rent,” & “maybe it’s bad that Wall St companies profit off mass surveillance, manufactured housing crises, and caging people”— Alexandria Ocasio-Cortez (@AOC) April 29, 2022
Early in the report below. the NBC station in Philadelphia shows the top three (of four total) candidates for the Democratic nomination for an open seat in the US Senate in the swing state of Pennsylvania. The report is lacking journalistically but is telling when we learn that the two leading candidates. Lieutenant Governor John Fetterman and US Representative Conor Lamb, are stressing that they can attract votes of moderates and conservatives, independents and Republicans, in the general election.
Neither Fetterman- the more liberal/left of the two- or Lamb professed support for Medicare for All, even after a pandemic in which millions of Americans lost health care as they lost their job. If they had done so, they might have been identified with progressive policies, and they didn't want to risk that in a Democratic primary race. Any interest- in a Democratic primary- in energizing their own party's base is abandoned.
If this is how "the extreme far-left is taking over," it would be disturbing to see what it would look like if moderates have been taking over. Which, truth be told, they have.