Some pundits have been predicting this for months. Not sure, but I may have posted such an article last year some time.
At least one is also predicting that a number of moderate Ds in swing districts will fall, not to Republicans, but to squad-like hard-left Democrats.
I think that's a bit less of a possibility, but it could happen.
One guy last year was saying that one very likely outcome of the coming election is the death of the moderate Democratic party for a decade or more and, by extension, the death of Democratic power nationally for an equal period of time.
How?
With moderate Democrats falling to Republicans, the hard left will seize control and will fundamentally rewrite the path of the Democratic party into a true socialist, give everyone free *expletive deleted*it by taxing one billionaire, platform.
But, they won't have enough power to push their agenda nationally, so the Democrats will become increasingly marginalized.
Moderate and centrist Democrats will push their support to centrist Republicans or will simply sit out all together.
I don't know if any of that will come true, but the way it looks right now is that the Democrats are facing a calamity of near Biblical, Old Testament ANGRY GOD proportions...