Hillary Clinton is a neoliberal, and the neoliberals are the enemy of both socialists and progressive capitalists. Unfortunately, her chief opponent is Donald Trump, who is — in addition to personally being a dangerous buffoon — is not only a neoliberal but is at least leaning towards fascism, and fascists are the enemy of everyone but themselves.
I'm sure that Clinton and her campaign staff threw the most glorious party when Trump was nominated. She can do anything she wants because, well, what's the alternative? Trump? Please. And Clinton wants neoliberalism. She's built her career around delivering neoliberalism to the capitalist class. And why shouldn't she? Shilling for the capitalists pays well, and with a little artful misdirection, gets votes. Clinton is a politician, and that's the job: get elected and get paid. (Sanders, who nearly won the nomination, is definitely not going to get paid, and wouldn't have even if he had won the nomination and subsequent election.)
But Clinton is not herself a capitalist. She doesn't have a personal, direct interest in neoliberalism. She has money, but not money. She is, fundamentally, an employee. We'll never move the Koch brothers away from neoliberalism, but we can move Clinton. We just have to give her a good story to tell.
Clinton would like to go to Wall Street and say, "I delivered. You're getting pretty much everything you want: neoliberalism, globalization, trade deals, global intellectual property monopolies, a fragmented and powerless working class, and all the money. All I had to give up was some stupid shit that didn't pay anyway. Pay me. Boards of directors. Speaking fees. Book deals. You know the drill. I want to wipe my ass with $100 bills."
Ideally, we'd like Clinton to go to Wall Street and say, "Fuck you. You and all your money can't win an election, so you and your money are useless to me. I'm not one of you, but I am President of the United States, and none of you will ever be President. I had to throw you under the bus to get elected, and it was totally worth it. My advice is to get to Lichtenstein right now; the people are assembling torches and pitchforks even as we speak."
Ah... a lovely fantasy, but it's not gonna happen.
We could, however, if we worked hard, force Clinton to go to Wall Street and say, "Let me be blunt: you guys are seriously fucking your own shit up, and I cleaned up your mess. I had to give up a lot of what you want, but you want too much. You still have power, you're still the ruling class, but seriously: if I had tried to give you everything you want, you'd've ended up with Trump, and you're just as scared of him as I am. So you owe, and you're going to pay me — boards of directors, etc. — not because I gave you everything you wanted, but because I gave you everything you needed, your lives, and perhaps more importantly, your power. You need me, I need you, and if you don't pay me, you're going to end up with another Sanders or Trump, or worse."
Even with the current material and political situation, we can do better than simply passively accepting neoliberalism because scary Trump! The capitalist ruling class is worried, and the political class is worried.
Trump and Sanders did much better than expected. Trump broke the Republican party, and at best the Republicans will form the core of a fascist party that could get enough support to stage a coup, perhaps even a successful coup. The Democratic party only just barely staved off the Sanders threat, and they shouldn't be confident they can easily defeat the progressives in 2020 or 2024. To survive, the Democratic party absolutely must purge the Sanders progressives, and keep them from forming a viable second party.
If we simply say, "Clinton, because scary Trump!" Clinton will know she can get away with purging the progressives. She knows she can get away with the TPP, only a token increase in the minimum wage, abandoning free college tuition (maybe lower the interest rate on student loans a point), busting unions, promoting monopolies, because hey! neoliberalism is better than fascism, right?
Politics is generally, and very obviously in this election, a chicken game. The only way to win a chicken game is to throw the wheel out of the car and say, "Either you swerve, or we both crash." If Clinton believes that progressives will swerve, if they'll vote for her in 2016 and 2020, and vote for another neoliberal Democrat in 2024 because scary Hitler! and scary Stalin!, she won't budge. But she is a politician, and she won't lose on principle.* If she believes she has to deliver a progressive agenda or lose to Donald Fucking Trump (how humiliating would that be?), then she'll deliver.
*Trump will lose on principle, because then he or his more strong-willed successor gets to use the classic fascist "stabbed in the back" narrative. Trump and his supporters don't want to win an election, they want a real no-bullshit dictator. Actually winning the election would be a disaster.
I don't have much hope, though. There will always be a scary Trump! and progressives fall for that con every time. The one thing that progressives seem completely unable to do is fight for what they want when the going gets tough. Y'all will yak yak yak and vote for Sanders when it's easy, but he loses one little nomination, and y'all just give up and go home.