THE best tribute to a troublemaker is that he has more admirers in death than in life.

Bob Crow, the general secretary of the Rail, Maritime and Transport union who died horribly young last week, made his exit with a bigger fan club than most. The chances are he would not have cared for the honour.

Few of the eulogies did not carry the whiff of hypocrisy. There was Boris Johnson, fresh from calling for a ban on strikes if ballots fail to meet his requirements, praising "Bob" as "a fighter and a man of character". There was Ed Miliband, honouring Crow as "a major figure in the Labour movement", one "loved and deeply respected by his members". Forgotten was the fact that the Labour Party expelled the RMT in 2004.

When Tony Benn passed away towards the end of the week, the weird ritual was repeated. Downing Street and Labour were as one in their condolences and, supposedly, their admiration for the 88-year-old. Such, it seems, is the fate reserved for socialists: marginalised in life, lauded in death. But it would be a mistake, a big one, to confuse the grand old parliamentarian with a trade unionist who, as they say, never failed to do the business.

In life, Crow earned that best of tabloid accolades, "the most dangerous man in Britain". Benn also earned the citation in his day. The difference was that the trade unionist secured rights and wages for his members, time and again, while the Labour visionary (if that's your taste) could make no such claim. Benn's attempts in a brief ministerial career to support workers' co-ops, from UCS to the Scottish Daily News among others, came to nothing. Crow was feared because he succeeded.

That was worth remembering amid the words from David Cameron or Nick Clegg's tribute to "a fighter and a force". You will look in vain for the support offered by these individuals to Crow's union during an industrial dispute. The best such types manage is lip service to the principle, but never the practice, of trade unionism.

Miliband's efforts to separate Labour from the movement that founded his party - and handed him the leadership - would be one example. Another would be the anti-union legislation enacted by the Tory tribe and left untouched by Miliband's predecessors. Benn would have objected eloquently. Then what? Those who idealise Crow disliked what he stood for when they did not detest it, but what they really hated was his effectiveness. Benn spent most of three decades as a self-regarding national treasure.

Ken Livingstone, another who wasn't always Crow's biggest fan, described RMT's victory best. "The only working-class people who still have well-paid jobs in London," said the former mayor, "are his members. With the passage of time, people will come to see that people like Bob Crow did a very good job."

It's a striking testimonial. The hopes and chances of those who keep England's capital running have been ground away to almost nothing in a generation. They are the reality behind those Gini inequality coefficients. Crow is nominated as the last working-class hero in part because of his achievements as a negotiator, but in part because he can be depicted as anomalous. He was, as the tabloids would also say, "a dinosaur".

The victories can be explained easily enough. Crow became the RMT's general secretary in 2001 just as rail travel was beginning to revive. Despite the flabbergasting failures of privatisation and doubts over safety - issues he pursued relentlessly - there was, and remains, a passenger boom. Secondly, Crow was in an industry that could still be brought to a shuddering halt by its workers. Few other trade unionists now have that advantage.

Nevertheless, the RMT has been more than the exception to a rule. Under Crow's guidance it has refused to settle into complacency or into the apathy that has formed like rust on the popular will. Add Thatcher's depredations to those states of mind and it isn't hard to see why a union capable of defending its members would be looked on as out of step with unforgiving modern times.

Complacent types will tell you, sometimes with straight faces, that if workers are no longer unionised that's because there is "no need". This happy thought implies either that all employers have become benign, keen to share the fruits of labour equitably, or that those who make the claim have a problem with facts.

Apathy is more potent, in any case. Unions falter because, it is said, there's "no point". To many, that claim makes sense. The odds are stacked high. The rules on strike ballots alone are a standing inducement to employers to reach for lawyers. If that fails, footloose capitalism is not above blackmail. We saw as much during the Grangemouth dispute. Ineos, not the Unite union, was "holding the country to ransom" with its closure threats.

It is a mistake, though, to assume that trade unionism is in unstoppable decline. The truth is more complicated. In 2012, there were 6.5 million union members in Britain. That was actually an increase of 59,000 from 2011, a year that saw union numbers fall by 177,000 in the public sector. Membership generally is only half of its 13 million peak in 1979, but unions still represent 26% of employees. A degree of stability has been achieved.

Whether it lasts is another matter. Fully 36% of union members are aged over 50. In 1995, the equivalent figure was 22%. Contrary to the usual cliches, 36% of trade unionists are in "professional occupations", a category that accounts for only 20% of the wider work force. You could infer, then, that those who need unions most are the least well represented.

Who needs unions? According to a report compiled for the Joseph Rowntree Foundation last December, a little over half of the 13 million people in Britain defined as living below the poverty line are in working households. If the job doesn't pay and your employer is happy to let the state top up low wages with tax credits, you need a union.

This month, equally, the Coalition was forced to admit what was long suspected: zero-hours contracts are far more prevalent than politicians were prepared to admit. The new estimate for 2013 is 583,000 jobs in which there is no liberty of choice or security. If you are trapped in that barbarism, you need a union.

Crow and Benn would probably have agreed about causes and effects. The latter would no doubt have talked (ponderously) about the infernal ways of capitalism. The difference between the two, though, was profound. In as much as he could, the RMT man did more than most to oppose the pernicious assumptions of the age. Tony Benn's self-seeking career simply became New Labour's excuse to declare socialism passe.

You can honour Crow, rightly enough, for what he achieved for 80,000 RMT members. Then ask yourself: how would those workers have fared without their union and their general secretary? Trade unionism survives because of need, and because, time and again, economic justice is not granted by those with power. It has to be won.