People seem to think Sanders big pro-establishment turn was in 2016, but the first I can find is from two decades prior in 1996, during a Nader/Sanders feud.
One has to wonder how the US would have turned out if Sanders actually headed the advice of Ralph Nader back in 1996, rather than blatantly ignoring him.
The dems have 0 right to bitch about a third party: the most successful third party candidate in recent history was Ross Perot, and he got magnitudes more support ("spoiler votes" from the gop) than Nader, and I don't see right wingers demonizing him as a "democratic operative".
If anything he has found a bit of a cult following for establishment-critical right-wingers who look up to him, rather than demonizing him for "costing us the presidency". He was still allowed to meet with GOP leaders and what not, and people still listened to his opinions.
Perot received 18.9% of the popular vote, but did not win any electoral votes. He won support from across the ideological and partisan spectrum, but performed best among self-described moderates. Perot ran for president again in 1996, establishing the Reform Party as a vehicle for his campaign. He won 8.4 percent of the popular vote against President Clinton and Republican nominee Bob Dole.
Though he quieted down, seeing the best path as influencing the GOP, he didn't really do an about-face on the issues he was passionate about, he never started shilling that he was "wrong about NAFTA, NAFTA is actually great".
Meanwhile
Sanders rejected the Nader path for over two decades. Two decades ago Nader proposed a pragmatic strategy, like "planting an acorn", only to be scorned by a pro (Bill) Clinton Sanders response:
http://archive.is/RlZnu
Left Out: Bernie Sanders and Ralph Nader Part Company
Ralph Nader rips into Sanders for supporting Clinton instead of his own non-mainstream campaign — a prelude of things to come in 2000. BY KEVIN J. KELLEY
November 13, 1996
... In an interview prior to his speech last Sunday to an overflow crowd at Saint Michael's College, Nader accused Sanders of putting "personal political survival" ahead of the principles the Independent socialist has always espoused.
Nader theorizes that "Clinton's people told Bernie he had to support Clinton or else they would help the Democrat [Jack Long] in the congressional race." The Democrats' promise to bestow a subcommittee chairmanship on Sanders if they captured control of the House may also have encouraged him to cuddle up with Clinton, Nader suggests.
"Supporting me would not have been the most courageous act of his career," Nader says of his erstwhile ally. "You're not a real progressive if you don't work to build an alternative to the Democrats — which is something Bernie Sanders says he stands for. You've got to plant an acorn, which is what I was trying to do."
Sanders does not exist in isolation, he has an appeal to a part of the electorate. If Sanders did not exist, the vacuum would have allowed someone else like Nader to fill the role.
When a keystone figure in politics falls, something else comes up. That is how ISIS was formed, thanks to the vacuum left by Saddam (and to some extent Assad's weakened state). Obviously ISIS isn't a role model of any sort, but an example of the political vacuum concept, and how keystone figures work in politics.
It still intrigues me Sanders claims to adore Eugene Debs, someone who actually formed his own party, while looking with contempt at Nader. Eugene Debs never would have existed if some "anti-establishment" fraud was actively siphoning away support at the time.
And today his endorsement of Biden isn't much different than the comparison Slavoj made in 2016
And what about poor Bernie Sanders? Unfortunately, Trump hit the mark when he compared his endorsement of Hillary to an Occupy partisan endorsing Lehman Brothers. Sanders should just withdraw and retain a dignified silence so that his absence would weight heavily over the Hillary celebrations, reminding us what is missing and, in this way, keep the space open for more radical alternatives in future.
Or Alyssa Milano and her role in sexual assault activism.
Ralph Nadar also, despite being a militant progressive, didn't alienate a huge part of the electorate with needless culture war antagonism. The irony is that he could be considered someone with a wider tent in that sense:
https://en.wikipedia.org/wiki/Unstoppable_(Nader_book)
Unstoppable: The Emerging Left–Right Alliance to Dismantle the Corporate State is a non-fiction book by American consumer advocate Ralph Nader, published in 2014 by Nation Books. Nader argues that there are many issues which progressives, libertarians and conservatives can agree on, such as opposition to "free trade" agreements, too much Wall Street influence in Washington, opposition to "corporate welfare", preservation of civil liberties, opposition to foreign military entanglements, etc., and that by working together they can defeat entrenched interest groups and achieve their desired policy outcomes.
... Reviews in both conservative and liberal publications tend to focus on Nader's career and on describing the content of the book.[4][5] However, a review in Alternet suggests that "The legendary consumer advocate has lost his political compass."
Its pretty funny that alternet deleted their angry political gatekeeping review, because that action rightly makes their behavior appear manipulative: http://archive.is/LW0bF
Ralph Nader Wants You to Join Right-Wing Libertarians to Solve America's Problems: What Could Possibly Go Wrong?
Alternet is, unsurprisingly, also a militant Russiagate truther outlet, and pushes various other pieces of pro establishment propaganda: http://archive.is/UrOYO
Julian Assange was promised a Trump pardon if he would lie about Russia’s DNC hacking: lawyer
I personally think there's an incredibly strong case Sanders was robbed of the 2016 nomination by some election/voter fraud.
I don't think that's the case in (other than Iowa and exceptions) most of 2020, once the non-Biden candidates dropped out it seems like he got undeniably stronger support than Sanders.
Biden, while stupid and corrupt, doesn't have the same amount of militant critics that Clinton had to the point where it became a joke in itself.
Nader has a legacy not only in his nonprofit work, but even political proposals:
Indeed, 16 years before Bernie Sanders staked his Democratic primary campaign on a "Medicare For All" plan, Nader pushed for a Canadian-style reform of the American health-care system. Speaking to an audience in Philadelphia outside of the Republican National Convention on July 31, 2000, just months before the election, Nader argued forcefully that "the time is long overdue for Americans to join other Western countries and get universal health-care coverage. The best way to advance health care in this country is to get these giant corporations out of health care and replace them with nonprofit institutions." Gore, meanwhile, spoke mostly about preserving Medicare and incrementally increasing the number of people with insurance.
Health care wasn't the only issue Nader was ahead of his time on. During the campaign he railed against the "criminal injustice system" at a time when national Democrats were still confident that their 1994 crime bill was responsible for bringing the rate of violent crime down rather than, as we know today, exploding the prison population and adding trillions to state and federal budgets. Nader's thinking on crime and prisons has slowly become the default conventional wisdom within the Democratic Party, albeit with a more explicitly woke anti-racist appeal than Nader made, with last year's nominee, Hillary Clinton, promising systemic reform to address racist policing practices and their disproportionate impact on minority communities.
Nader was also the first national figure to endorse a financial transactions tax, which will be one of the most important tools future Democrats will use to pay for their expansive plans to extend the social safety net. While Democrats remained reflexively pro-trade into the Obama administration, Nader pushed for a renegotiation of NAFTA to strengthen labor protections. He called for a significantly higher minimum wage and European-style parental leave and daycare policies.
Anyways I'd argue that the Debs of our era is undeniably Ralph Nader, and that Sanders really needs to take a closer look at Debs' life if he insists on idolizing him:
When Bernie Sold Out His Hero, Anti-Authoritarians Paid
SEPTEMBER 19, 2018
...Worse than other such sheepdogs, Sanders, from his earliest years in politics, has attempted to seduce anti-authoritarians by identifying with Debs but then, for career expediency, ignored what his hero’s life taught him.
Debs, in his twenties, was a successful Democratic politician but gradually became radicalized by his experiences. In his late thirties, when jailed for leading the Pullman Strike, it became clear to Debs that both the Republican and Democratic Parties were owned by the ruling class.
Sanders’s initial dissent propelled his political career; his ultimate obedience kept his career intact; and by 2017, polls reported that he was the most popular politician in the United States. Sanders knows full well the life of Eugene Debs—and the price Debs paid for being a genuine anti-authoritarian who disobeyed illegitimate authorities.
Anyways
The lack of anti-establishment action has held back left-wing dissidents inside the US.
The right wing has a lot of flaws but at the very least they were able to get an anti elitist guy in office, at the protests of party elite:
http://archive.vn/ywHPg
How the G.O.P. Elite Lost Its Voters to Donald Trump
March 28, 2016
While Trump has undeniably compromised and arguably "sold out" on at least a few issues, he's continued to shake/reform the core of the GOP in a direction his base prefers and that MSM despieses:
http://archive.vn/hxqfN
Trump’s Takeover of the Republican Party Is Almost Complete
April 3, 2019
In Ohio, a crucial battleground, the state party chairman had repeatedly chided Mr. Trump in public, amplifying the concerns of Gov. John Kasich, a Republican dissenter. In New Hampshire, the party chairman harbored deep, if largely private, misgivings about her party’s nominee. The Republican Party of Florida was listing, hobbled by local feuds and a rift between donors loyal to Senator Marco Rubio and former Gov. Jeb Bush and those backing the man who humiliated both in the primaries.
Those power struggles have now been resolved in a one-sided fashion. In every state important to the 2020 race, Mr. Trump and his lieutenants are in firm control of the Republican electoral machinery, and they are taking steps to extend and tighten their grip.
It is, in every institutional sense, Mr. Trump’s party.
Learning about this is essential if any left-wing party elite are to be overturned
there doesn't seem to be anything here