These are still tough times in America. Joblessness is rife, growth rates are slow and all sorts of fiscal crises loom in government. The impact of the Great Recession rumbles on and blights the lives of tens of millions of ordinary Americans.

No one should be surprised, then, that America's political system is on the hunt for a scapegoat – some bunch of villains on which to blame the nation's woes. But how odd that the current candidate turns out to be the labour movement in general, and public sector unions in particular.

Across the US, politicians are railing against the terrible abuses of powerful union bosses, especially in state government. Many of those politicians are Republicans. But far from all of them. In New York, the freshly minted Democratic governor, Andrew Cuomo, has joined the backlash, asking for a wage freeze for all public workers. In many states, new laws are being considered that will trim union rights, such as the ability to get fees from their members or the right to negotiate a union contract or even form a union at all. In Ohio, a new Republican governor wants to ban strikes by public school teachers. In New Jersey, Governor Chris Christie's attacks on unions have become a YouTube sensation.

What is perverse about this trend is just how vastly it misunderstands what went wrong with the American economy. No one is denying that this is a time for belt-tightening. Or that some unions have problems. Or that some union contracts look over-generous in austerity America. But the fundamental truth remains: powerful and reckless unions did not cause the Great Recession by rampant speculation. Nor did an out-of-control labour movement cause or burst the housing bubble. It was not union bosses who packaged up complex derivatives to sell in their millions and thus wrecked the economy and put millions out of work. Nor was it union bosses who awarded (and continue to award) themselves salaries worth hundreds of millions of dollars for doing nothing of social value. Neither was it the union movement that was bailed out by the taxpayer and then refused to change its habits.

All that was the work of the finance industry.

Yet, as America continues to search for solutions to its economic problems, it is the labour movement, and not the banking sector, that is getting it in the neck. This is despite the fact that many unions, especially in such cases as the bailout of Detroit's automakers, have proved themselves highly flexible in sacrificing wages and long-held workers' rights in order to preserve jobs. Meanwhile, the finance industry, where true and meaningful reform has failed to happen, still squeals as if President Obama were a raving socialist. Or, in the helpful and moderate words of Blackstone chief executive Stephen Schwarzman, "It's like when Hitler invaded Poland in 1939."

No, Mr Schwarzman, it is not like that at all.

In fact, American bankers and big corporations are flush with cash and generous tax breaks and back to most of their old habits (like grotesque bonus payouts, refusing to loan money and offshoring jobs and profits). But in the political world, it is the good union jobs that are suddenly an evil thing, when, in fact, a job that allows someone to afford their house and have good healthcare is a boon to the economy. Certainly, more of a boon than a multimillion dollar bonus to a financier who is already rich. A decent union job is a mini-stimulus package at a time when jobs are scarce and in a country where real wages are all too often stagnant or declining.

Not that the politicians care. Demonising labour has a long and dirty history in America, despite its historical weakness and low rates of union membership. Now, in times of trouble, American politicians have fallen back on the oldest stereotype they know: the evil union. Yet never has demonising the labour movement and the hardworking Americans it represents seemed more out of place.