IN TAHRIR SQUARE and Homs, Egyptians and Syrians have risked their lives to demand basic democratic freedoms. In Britain, that nation of shopkeepers, the young take to the streets to smash windows and steal trainers and television sets. Greeks are rioting because they can see their economic future being washed down the drain of the euro. And for the past few weeks in New York City many hundreds and sometimes thousands of young Americans have been marching, or camping out in Zuccotti Park in the financial district, to “Occupy Wall Street”, because they are demanding—well, what exactly?

To judge by the diversity of their slogans, placards and websites, you pays your money (metaphorically) and you takes your choice. But there is no mistaking the gist.

These people do not believe that the business of America should be business. A “Declaration of the Occupation of New York City” summons all those who feel “wronged by the corporate forces of the world”. Corporations “place profit over people”, “run our governments”, take bail-outs “with impunity”, poison the food supply, block green energy, “perpetuate colonialism at home and abroad”, muzzle the media and use student loans to “hold students hostage”. The protests have already spread to Los Angeles, Boston and Chicago, and were this week heading towards the nation's capital. Explicitly invoking the spirit of Tahrir Square, the organisers of a rally planned for Freedom Plaza in Washington, DC, are demanding “just solutions to the crises we face”. In “creative acts of civil resistance” demonstrators will demand peace, freedom and “inherent rights”, including the inherent right “to grow edible natural food”.

It is easy to demand “just solutions”. But this is so far a movement without detailed policies. You might call them the Rorschach protests. Politicians and newspaper commentators stare at the inkblots and see what they want to see. If they see nothing very coherent, they offer suggestions of their own. For example, Nicholas Kristof in the New York Times, moving from the sublimely vague to the ridiculously precise, advises the Wall Street demonstrators to demand a financial-transactions tax, the closing of the “carried interest” loophole and stricter capital requirements (he suggests the Basel 3 standards) for big banks. Good luck with those catchy slogans, Comrade Kristof.

What the broader American left would love to see in the protests is a progressive counterpart to the conservatives' tea-party movement. And why should that be so impossible? The tea parties, remember, also started with little more than a (strikingly ungrammatical) cry of pain. “This is America,” yelled Rick Santelli, a financial reporter, from the Chicago futures exchange in 2009. “How many of you people want to pay for your neighbour's mortgage that has an extra bathroom and can't pay their bills?”

Mr Santelli's televised rant against bail-outs has gone down in history as the birth harangue of the tea-party movement, which went on in double-quick time to capture the Republican Party and yank the whole of American politics sharply to the right. Like the Occupy Wall Street crowd, the tea-partiers did not have much by way of detailed policy when they started. That lot wanted to bash big government and restore individual liberty. This lot wants to bash big business and restore social justice. So why can't Occupy Wall Street become a tea-party movement for the other side, one that might jolt the Democrats out of their torpor, tug them left, and switch back on some of the electricity that Barack Obama generated when he was running for president?

One reason is that nothing sucks the energy out of a protest movement faster than winning power. And although Mr Obama still has his tax-the-rich moments, he knows he will not be re-elected by lurching too far left. The man who could use a fresh wad of donations from Wall Street as 2012 approaches is not going to align himself with those who would tear it down. Nor they with him: to many of the demonstrators, all politicians, including Mr Obama, are “Republicrats”, each as rotten as the other.

You've had your revolution already

The other reason to doubt whether Occupy Wall Street will become a tea-party movement of the left is its fixation on protest. But Zuccotti Park is not Tahrir Square and America is not Egypt. It is not even France. In France street demos are tolerated, sometimes glorified, as a way to blow off steam and win the attention of deputies who neglect voters or forget their election promises.

America is different. It is, indeed, the sort of democracy that some people in Tahrir Square lost their lives asking for. With endless elections and permanent campaigns, it is exquisitely sensitive to voters' wants. Its parties are bitterly polarised, so it is wrong to say that its politicians are all the same. It has its party machines, but groups that organise hard can use the primaries to prise them open. True, elections cost money; but Mr Obama proved that money soon flows to unknowns with momentum.

The tea-partiers grasped all this. They, too, took to the streets. Some strutted about in tricorn hats. But at the same time they learned their way around the machinery of elections and how to scare the bejesus out of any candidate they did not like.

The people behind Occupy Wall Street could follow suit if they wanted. Yes, they have every right to protest. Marches and sit-ins have played an honourable part in American history. The right of the people peaceably to assemble is enshrined in the first amendment. Nothing in the constitution says that you have to have a 12-point policy plan from McKinsey, or the permission of the New York police. If nothing else, these protests highlight the misery of millions during the present slump. But to bring about real change in a real democracy you also have to do real politics. It just takes work—and enough people who think like you.

Economist.com/blogs/lexington