We are approaching another election disaster for the Democrats, so establishment Democrats are already shifting into scapegoating the slightly less corrupt, non-corporate wing of the party - progressives.

It is a neat and convenient explanation, and one that Democrats have been returning to for decades: Whenever their electoral prospects dip, it must be the fault of the party’s left flank. What’s the solution? Look no further than the electoral success of Bill Clinton—or, for that matter, Joe Biden—and the answer is clear: The party’s only hope of success is by tacking rightward.

There are several problems with this analysis. For one, the members of “the Squad,” for all of the media attention they receive, are still backbenchers with little sway over the party’s legislative agenda: They are but six of the 222 Democratic members of the House. They’re also far more focused on creating equitable economic policy than on any of the things mentioned by Allen. Nor, it’s worth underlining, are they the engines of those policies.

When you think about it, Third Way Dems are actually using the exact same talking points of the Republicans, to bash their progressive base.
None other than Hillary Clinton is leading the charge in blaming progressives for the sweeping defeat that has not happened yet.

None other than the party's 2016 presidential nominee, Hillary Clinton, has said liberals risk costing their party precious political power by pandering to voters in areas that are already Democratic, with little to no risk of swaying the control of Washington.
...
“If Democrats brought home expansive climate action, a federal minimum wage of at least $15, paid leave, police reform, and ‘Medicare for All,’ we would win in a landslide,” she said. “The problem is that these are not getting done, year after year, even while basic necessities like housing and health care keep getting more and more expensive.”

“The path forward is to actually enact policies that address the pain people are feeling across the country, not pretend that pain doesn't exist,” Bush said.

What? Deliver on the promises for helping the working class, rather than blame, say, the Senate Parliamentarian for why you can't do anything? That's radicalism!
So you would think that if progressives were responsible for all of the election ills of the Democrats, that this would be reflected in the actual elections.

In fact, the only election where the corporate wing of the party clearly did better than the progressives was the huge wave election of 2018. Every other election the progressives either did far better, or did around the same.
Of course the Democrats are as bad as Republicans anymore when it comes to ignoring the facts. The Republicans think Trump was a great and radical president that opposed the elites (as opposed to his traditional, corporate Republican record), and that Biden is some sort of radical socialist (as opposed to his neoliberal, corporate record).
Only the progressives in the Democratic Party, and the Libertarians in the Republican Party, are talking about actual material policies. The mainstreams of both parties have limited themselves to the culture wars, which Americans really hate, and then they blame the culture wars on the progressives and libertarians.