There’s no money left so the left is collapsing

[AiA in Atlanta]

A robust middle-class is required for the kind of capitalism we are used to yet American conservatives have engineered its collapse over the last four decades.

Just saying it doesn't make it true.
Explain how you think they have "engineered" it to collapse over the last 4 decades...

If it wasn't for American conservatives, you wouldn't have the kind of capitalism you are used to.

There was a time not so long ago that the American middle-class simply didn't exist in the way we understand it today. Then came Republican (a Progressive) President Theodore Roosevelt and his "Square Deal" and the middle-class began to grow. Some decades later his 5th cousin President Franklin Roosevelt took office and in came the "New Deal." After WW2 the American middle-class really took off largely in part because of the New Deal. By the late 1960's the Republicans (conservative ones) began to be able to roll back the gains that gave America its robust middle-class. When Reagan took office large chunks of the New Deal began to be dismantled en masse ... a process that continues today. George H Bush, before Reagan selected him to be his running mate, called Reaganomics "Voodoo Economics" because the idea that one can give everything to the elites and the corporations and have it "trickle down" (Trickle Down Economics = Reaganomics = Voodoo Economics) to the little people is Magical Thinking. That is what has kept American running for decades now, a belief in magic.

That being said, this isn't really a Right v Left issue. There is no real Right or Left left in America. Instead, there is one party with two wings, and that party is the Corporate Party. And it isn't just America - it is happening all over the world. The middle-class is hollowing out and more and more people are entering the upper classes. Hillary Clinton is a corporate candidate. Jeb Bush is a corporate candidate. Multinational corporations are fine with either of them. Why? Because they know nothing will fundamentally change. The middle class will continue to hollow out and the elites will continue to get wealthier.