Sanders was running against Hillary as a Democrat, within the Democratic Party. That made for tacit acceptance of the party's principles.

Plus, the leaked emails showed that while the DNC claimed publicly to be neutral, the organizers were secretly in league with Hillary. If there was nothing wrong with their "party politics," why did they keep it secret? Why did Schultz resign? Brazile pointed out in her book that Schultz made a deal with Hillary in 2015 that Hillary would control the DNC as long as she raised money for the DNC. So it was a quid pro quo business arrangement. Sounds like cynical neoliberal thinking to me (rather than the idealistic, uncompromising, progressive kind).

The New Deal wasn't a committee-written, bastardized piece of legislation, nor was Lyndon Johnson's Civil Rights Act. Those politicians knew how to use a crisis to ram through needed legislation. Obama wasted his crisis and was no FDR. He was a technocratic, neoliberal manager, not a transformational figure. Trump was more transformational and historically important than Obama or Bill Clinton.

I don't say Democrats forced Republicans in the sense of holding a gun to their head and giving them no other option. In the article I even spell out another option that might have been taken. But Democratic triangulation plus the confines of the two-party system plus the sociopathy of Machiavellian politics did give the Republicans no other politically viable option. The Republicans had to move further to the right than the Democrats were moving to have a chance at winning elections. And that strategy paid off in the short term, as Gingrich, Karl Rove, and Trump showed. But the strategy looks unsustainable and self-destructive.

Your Marxism comment is neither here nor there. Also, your condescension makes you look foolish.