George Galloway was uniquely qualified to mobilise the anti-mainstream party vote in the Bradford West by-election. While Labour will be tempted to dismiss his incredible victory as a one-off, the result tells us something important about Labour. As well as being a "Galloway factor" and a "Bradford factor," there must surely have been a "Miliband factor" too.
Ironically, Mr Miliband has had a good fortnight. His response to the Budget, never an easy wicket for an Opposition leader, was seen as his best Commons performance. He played his hand well this week on the Conservatives' funding scandal and what he rightly called the "shambles" of the Government's response to the threatened strike by fuel tanker drivers.
Labour's surprise by-election setback is part of a pattern. Mr Miliband gets himself into good positions and then blows it. He is in danger of becoming a "one step forward, two steps back" leader. "He does a brilliant run through the other team's defence but doesn't shoot and then passes the ball back to our own defence," says one Labour frontbencher.
He shines – bravely, for example, taking on Rupert Murdoch's empire last summer – but then goes dark. In January, Labour angered the trade unions by accepting the need for public-sector pay restraint. But Mr Miliband didn't follow it through; he disappeared off the radar again. Such big messages need to be delivered a thousand times to cut through to the public. They need to be said as often as Labour accuses the Conservatives of being "out of touch". Attacking the Tories is the easy bit; Labour needs to do a lot more of the hard stuff.
The Labour leader is too cautious. He gives the impression of knowing where he needs to be but agonising about how to get there, consulting widely and trying to find a compromise that keeps everyone happy. Inevitably, what the public sees at the end of this tortuous process is a diluted version of what he really thinks.
There is a danger that Labour learn the wrong lesson from the Bradford by-election. Mr Galloway's Respect Party claims people want a stronger line than Labour offers against the Coalition's spending cuts. Such an approach might make Labour activists feel good but it wouldn't do the party much good. Its problem is that voters see it as addicted to spending; until it can convince them otherwise, it will not offer a credible alternative to the Government.
Mr Miliband knows it but doesn't show it. His words on the economy are too coded. He does have a long-term plan: a future Labour government would cut total spending but share out the cake more fairly through "switch spending". For example, Labour would cut the pay of senior public servants to allow rises for those at the bottom.
The problem is that this is eclipsed by the five-point plan, including a £12bn temporary cut in VAT, championed by Ed Balls, the powerful shadow Chancellor, who won't stop talking about need for a short-term stimulus because he is convinced George Osborne's cuts strategy is failing. Some Labour folk think Mr Balls may be right tactically but is unwittingly weakening Mr Miliband's long-term strategy because all the voters hear is Labour wanting to spend more (again). Being seen as "same old Labour" means the party cannot profit from the mistakes of the "same old Tories".
Labour has got to show it has changed. Above all, Mr Miliband knows he has to persuade the public Labour can be trusted with their money. Events offer a chance to convince voters that Labour is not in the pockets of its union paymasters.
Tory attacks on Labour over the tanker drivers' dispute have been crude and opportunist but will strike a chord with some voters. Mr Miliband cannot ignore them. He will have to take a tough line and shouldn't put it off.
The Tory funding controversy means there will never be a better chance to clean up the way political parties are funded. Mr Miliband should go on the offensive by accepting the proposal from Sir Christopher Kelly's Committee on Standards in Public Life for union members to "opt in" to paying the political levy to Labour rather than having to opt out. The unions won't like it but Labour should tell them that a wider prize is at stake.
Last year Mr Miliband backed down over plans to cut the unions' 50 per cent share of the vote at Labour's annual conference, fearing defeat on the issue at the conference itself. He may be tempted to fudge the issue again this year but should go for it.
The Labour leader needs to be bold, to surprise people and grab their attention. The party doesn't have to divorce the unions, but current events offer him the chance to show they do not run the party. He should take it.
I suspect Mr Miliband knows what needs to be done. The time has come for him to answer the big question: can he do it?