s far as Labour is concerned, Keir Starmer is now master of all he surveys. A landslide victory among the party’s membership was accompanied by his appointment of the national executive committee’s general secretary, and with it control of the party machine. In the past two weeks, his removal of Rebecca Long-Bailey from the shadow cabinet and changes to NEC voting mechanisms have cemented the Starmer ascendancy. Commentators who spent years howling about Corbynite authoritarianism demand more: the left must not just be thrashed but humiliated in the process. A year ago, the headline above one Times commentator’s column was “Jeremy Corbyn’s intolerance makes him unfit to lead”. Two weeks ago it was “Keir Starmer should finish the purge of Corbynism”. As Starmer eyes the best ratings of an opposition leader since the mid-1990s and the party begins to shrink the polling gap, his team can seemingly afford to shrug off their internal opponents. If criticisms from within are framed as the left versus the leadership, that suits the latter’s outriders, who can dismiss them as the petulant howls of discredited losers. But in an age of political unpredictability and fluidity, complacency would be unwise: just ask Boris Johnson who, three months ago, headed the most popular government in a decade, with a net approval of +26 (it is now –9). Starmer’s emerging Achilles heel is not his demoralised internal leftwing opponents: it is younger people and minorities. When Jeremy Corbyn’s Labour deprived the Tories of a majority in 2017, the party won the highest support among the under-40s in any election, including Tony Blair’s landslide. It also repelled more pensioners than ever, and given they constitute a quarter of the electorate and are motivated to vote, Labour did not win that election. Even in the 2019 rout, Labour’s lead among the under-25s actually increased. While Corbyn had dire approval ratings in the overall population at the last election, he enjoyed net support among ethnic minority voters. There are important exceptions, of course – Jews worried about antisemitism and some British Indian voters affronted by Labour’s support for Kashmiri self-determination – but Corbyn’s long involvement with anti-racism struggles and close alliance with figures such as Diane Abbott led many minorities to conclude he was a natural ally. This Monday, Starmer criticised the official demand of the Black Lives Matter “moment” to defund the police as “nonsense”, and expressed his loyalty to the police. This came three weeks after Starmer’s taking the knee in a social media post was met with raised eyebrows following criticism from black Labour party members over the failure to publicly deal with allegations of abuse toward senior black politicians. Defunding the police was never going to be part of Starmer’s policy package, but during a global uprising against systemic racism he could have taken a more constructive approach. He could have said he was not a spokesman for Black Lives Matter, that while he supported the police, reform was needed in a country in which most black people believe the police are institutionally racist. He could have pointed to the report put together by his own shadow justice secretary, David Lammy. He could also have championed investment in youth, social and mental health services, rather than relying on the justice system to deal with society’s ills. Younger people flocked to Corbyn’s Labour in unprecedented numbers for two reasons: first, their economic and social insecurity, from the housing crisis to student debt to low-paid work; second, they felt their progressive social values were under assault. They have no ingrained loyalty or sentimentality towards the party. Otherwise politically disengaged young people post in support of Black Lives Matter. If the suited former director of public prosecutions wants to pick a fight with the Black Lives Matter movement young people will judge him harshly for it. That nearly two-thirds of black and minority ethnic voters have seen Labour as their champion is unsurprising: as well as an inherently racist justice system, nearly half of black African Caribbean households languish below the poverty line, andblack, Asian and minority ethnic workers are far more likely to have insecure work and to live in overcrowded homes. These are injustices that cannot be fixed with tinkering or with half-measures: only transformative policies can be considered genuine remedies. For those who want the party to remain committed to radical change, the battle lines should not be drawn as “left versus right”, but judged on whether Labour is abandoning the under-40s and minorities. True, Labour is emphatic it retains the pledge, for instance, to scrap tuition fees, although it refuses to commit to any manifesto policies. But when none of the party’s recent economic statements mentions the climate emergency, that should be judged as betraying younger people who will suffer the worst consequences of this existential crisis. When Starmer sits on the fence on trans rights, the leadership should be taught a lesson: that for younger people, LGBTQ rights are an article of faith. From housing to jobs to education to public services, a test must be applied: does the radicalism of Labour’s policies meet the scale of injustice facing younger and minority Britons. For those within the party, from Momentum to the soft left Open Labour, a coalition should be built to hold the leadership to the policy commitments Starmer made in his election: that is, after all, his mandate. But more importantly, extra-parliamentary movements such as Black Lives Matter can communicate a message that is impossible to ignore: the support of the under-40s and minorities is not unconditional, it has to be actively sought, and if they feel the party has abandoned them, they will respond accordingly.