The fascinating thing though is that as the GOP moved further right, the Dems appear to have moved along with them, but keeping 3 steps behind at all times.
That's been due to the Dems' assumption that crumbs are better than nothing, that nothing always means political failure, and that compromise remains an option for both major parties, even in the face of strong evidence that the GOP long ago decided that stonewalling is what pays off.
If we as ordinary citizens had had any backbone left in the USA by around 1984, we would have started throwing general strikes, when we saw where Reagan was going with his union busting tactics and deregulation. But we didn't do that. We bought the whole "morning in America" thing --hook, line and sinker-- because it was much more attractive than the kind of financial discipline that Carter had been calling for.
However, in the mid-80s farmers were getting foreclosed on even as real estate investing boomed... and by 1992 it was pretty clear that "trickle-down" economics was BS, and nothing better symbolized the gap between the haves and have nots than Bush 41 not knowing the price of a gallon of milk.
But all we did then was elect a southern Democrat in 1992 and let that administration install "welfare reform". What that administration, its advisers and those several terms of Congress also did was further relax a lot of erstwhile restrictions on banks and investment firms.
Federal government got away with a lot of long term anti-worker moves through the Reagan and Clinton eras, by managing a rising economy quite well in the short run, so "it's the economy, stupid" tended to prevail, even as industry deregulation advanced only to the benefit of capital owners.
So "greed works..." for awhile. When there's bread on the table, Americans tend to figure "I've got mine, Jack." Clinton was re-elected despite having been impeached over lying about a sex scandal, because he did preside over an improving economy with a lot of job creation.
Anyway it was right there in the early 90s when the Dems first seemed to sign on to a form of Third Way centrism and so became the left wing of the Republican Party, moving to the right from then on in tandem with the Rs... particularly with respect to further deregulation and obeisance to other desires of the multinational corporations across all sectors of the economy. Global commerce on steroids, and a lot of winking at fine print in our laws about corruption.
The Dems' problems now arise from having tried to talk the talk of progressive social policy for so long, while not being able --or willing-- to back it up with legislation to match. The Rs have meanwhile sold in pretty well the idea that progressive legislation means oppressive taxation and "socialist" government. But they are a minority party, and it will be interesting to see what the progressive Democrats can do as candidates in 2022 and 2024.
While it's true that progressives are angry right now at Manchin and Sinema, there are a bunch of other pro-business Democrats, particularly in the Senate (thanks to lobbies of oil and gas, insurance and banking, health care industries), who are hiding behind those two characters.
Schumer waited a long time to get where he is now, but imo he's not the best leader for the Dems in the Senate at this point. He and Biden seem like two peas in a pod, in doggedly going for the crumbs, damn it. Pelosi is a better vote counter and leader, but she's aware that the GOP plus Manchin and Sinema are road blocks for progressive legislation coming out of this Congress. It's sad, particularly if the Dems can't keep their base interested enough to turn out in 2022.