The enduring ideology of the political establishment is the promotion and protection of the ruling class' interests--invariably at the expense of the working class. Both parties serve the same master, and because there are only two, the voters don't have much say in the matter. Progressives, like Bernie, who call out the billionaire donors are the exception to the rule. (More on him later.)

Seen from the leftist perspective, the overlap in the Venn Diagram is a consistent commitment from our politicians to put profits over people. It is why both George Bush and Barack Obama bailed out Wall Street (to give just one example of corporate welfare). It is why SCOTUS declared corporations "people" and campaign donations "free speech". It's why the U.S. has engaged in neo-imperialism over the land, labour, natural resources, and markets of developing nations. It's why the CIA assassinated democratically elected leaders in South America and Asia. It's why we've had decades of stock market growth while wages continue to stagnate. This is not accidental: the system is working as intended.

If Bernie had been elected in 2016 the outcome for the DNC would likely have been just as dramatic. If you want the Democratic party to be a leftist party, go make it one. We’ve literally seen a major party pushed to fascism. You know know change is possible.

I wrote this in another comment but I'll reiterate here. Bernie did not get a fair chance at the presidency. The DNC limited the number of debates (not allowing their favourite to be taken to task), they gave Hillary debate questions ahead of time, gave Trump/Clinton all the media coverage, etc. It is damn near impossible to succeed as a third-party candidate (sorry, Jill Stein) so a self-proclaimed socialist has to run as a Democrat and play by their rule book. And they don't even have to play by their own rules! (Court Concedes DNC Had the Right to Rig Primaries Against Sanders.) When AOC runs, they'll do the same thing and then she will spend her time in Congress backing establishment democrats. Please realize that the political elite would much rather shift to the right than to the left. The far left-wing actually threatens the profits of the wealthy.