Ken Livingstone will never again be mayor of London. His second defeat by Boris Johnson has ended one of the most colourful careers in British politics.

It’s hard to believe that the sad figure who left the stage today once electrified the political scene. As leader of the Greater London Council, Ken defied Margaret Thatcher at her most powerful. Thatcher was so unnerved by Ken’s bravado that she abolished the GLC, an act of spite that left London as the world’s only leading city without its own government body. In 2000, he defied another powerful prime minister, Tony Blair, to become the city’s first elected mayor. (Blair’s mistake was a classic example of how New Labour’s controlling tendency often backfired spectacularly.)

As mayor, Livingstone achieved a lot, notably the bold congestion charge scheme, helping win the 2012 Olympics and his dignified response to the 7/7 bombings. But his maverick nature became a weakness not a strength. Ken likened a Jewish reporter to a concentration camp guard – and compounded the offence by repeatedly refusing to apologise. It was the first of a number of insensitive remarks about the Jewish community.

The greatest indictment of Livingstone is that he lost to a Tory on a day when the Tories were routed in other elections across the country. True, he was fighting the Tory media as well as Boris Johnson, but that didn’t matter elsewhere. And in his prime he appealed to voters of all political shades. In 2012, even Labour voters found Ken unappealing. Tony Blair was wrong in 1999 to try to block Ken ahead of the first mayoral election. But in 2012 Labour made the costly mistake of giving Ken one last chance.