Give Federal Reserve head Janet Yellen credit for one thing: She has united Democrats and Republicans — in their hatred of her and her organization.

Yellen went before Congress last week and elected officials from both parties held a disdain-a-thon.

Democrats basically echoed candidate Bernie Sanders, whose mantra is that America is unfair; the rich keep getting richer thanks to government policies and all strata of the middle class are getting a fastball thrown at the back of their ear.

The Republicans come to the same conclusion but from a different angle. The Fed, says the leading Republican presidential candidate of the moment, Donald Trump, has created bubbles in the financial markets and it’s going to end badly.

It used to be during these congressional hearings that you could close your eyes and tell the party affiliation of the person speaking just by barbs and blossoms thrown. Not anymore. Both sides blame Yellen, and by extension, the administration.

Americans are way ahead of our elected officials. A survey released by the Pew Research Center last week revealed that 65 percent say the economic system in America “unfairly favors powerful interests.”

The attitude is bipartisan, with 54 percent of Republicans and 73 percent of Democrats agreeing.

And — this is important — this poll was taken between last August and October. That’s before the stock market started tanking, the Federal Reserve raised interest rates for the first time in eight years and before Yellen was peppered with questions about the latest crazy idea — “negative interest rates.”

Negative interest rates are simple to explain: People put their money into a bank or US government securities and instead of getting interest on that deposit, they have to pay a fee for the privilege.

No Republican or Democrat said it in so many words, but it was clear this would be the last straw.

If the Fed decides to go the way of Japan and some European countries in charging savers for the safekeeping of their money, expect massive backlash.

Some in Congress have already threatened to audit the Fed just on principle. Keep it up, the Fed’s critics say, and we’ll take a look behind the curtain to see what the least regulated of American organizations has been doing with the vast power it has to set interest rates, control the economy and change people’s lives.

An audit would probably start with the trillions of dollars of government bonds purchased by the Fed through an experimental program called quantitative easing. These bonds were bought, essentially, with newly printed money. The goal was to create more demand for Washington debt at bond auctions (from Washington itself) so that interest rates would hug 0 percent.

In any other auction (art, cars, win-a-date), that would be considered having a shill in the audience jacking up prices and lowering rates. But the Fed has gotten away with it.

Quantitative easing was supposed to get the economy humming again; low interest rates would lead to borrowing, which would lead to expansion, which would lead to Happy Days Are Here Again.

That didn’t happen. In fact, the US economy has had the slowest post-recession gain ever. And while the most widely followed of the nation’s unemployment gauges has dropped to 4.9 percent, the labor participation rate — which is the number of Americans in the workforce as a percent of the total population — is at a multi-generational high.

Yellen is a defender of the unemployment rate, until she is questioned about it by elected officials. That’s the only time she’ll bring up the fact that a broader gauge of unemployment — also produced by the US Bureau of Labor Statistics — shows joblessness at 9.9 percent.

People believe the economic system is not only unfair, but officials are lying to them on top of it all. Guess what — they’re not imagining things.

Give Federal Reserve head Janet Yellen credit for one thing: She has united Democrats and Republicans — in their hatred of her and her organization.

Trump and Sanders understand this. After they won New Hampshire, Trump was on MSNBC’s “Morning Joe” saying, “We’re being ripped off by everybody. And I guess that’s the thing that Bernie Sanders and myself have in common.”

Of course Trump and Sanders disagree about the right prescription, but, Trump added, “The only thing he does know, and he’s right about, is that we’re being ripped off; he says that constantly; and I guess he and I are the only two that really say that.”

Yellen has offered plenty of excuses as to why US economic growth has been so weak, and none of them places the blame on anything the Fed has done. “Headwinds” is the convenient excuse — problems in Europe, the slowing Chinese economy, drop in oil prices, currency wars, terrorism, and the list goes on.

The Fed chief hasn’t gotten around to blaming the cooties at Chipotle yet, but wait awhile.

So what really is the problem? All of those things (except Chipotle), but mainly the fact that the Fed has tried a stealth trickle-down economic policy. By keeping interest rates so low for so long, the Fed has created a secret tax on savers to bail out the US economic system.

And without their usual interest income, Americans have not been able to spend as they normally would. Consumers are said to be responsible for 70 percent of the economy. Take away their spending power and the usual dynamics of the American economy don’t work.

The Fed’s ultra-low rates forced people into the stock market even if they normally wouldn’t tolerate the risk. This is another version of trickle-down economics — make rich stock holders richer and hope some of the benefits flow down to everyone else.

With the stock market now in trouble, it looks as if this final hope of the Fed isn’t going to happen either.