Leading article: Diminished and discredited

In theory, Barack Obama should have been Bill Clinton's ideal candidate for US President. Young, bright, ambitious and bold, with an unerring popular touch, Mr Obama has so much in common with the former President. And, even 16 years apart, in such very different Americas, their messages of can-do optimism, social inclusion and change allow voters to think better of themselves. Whatever one thinks about Toni Morrison's remark about Mr Clinton being the first black US President, he can nonetheless be seen as a trailblazer for Mr Obama in this way, too.

If only, it is tempting to say, Mr Obama had not emerged as the main obstacle to Mr Clinton's wife winning the Democratic nomination, a great deal could have been different. The most exciting presidential candidate at least since Bill Clinton, and possibly since JFK, could have had perhaps the most accomplished US political campaigner on his side from the start.

Instead, something almost inconceivable happened. The former President, who had emerged from the White House personally tarnished, but still respected for his political and leadership gifts, managed to damage the formidable reputation he had left. Even as Hillary Clinton's stature grew, Bill lost what remained of his, stooping to petulance, sniping and – shamefully – even racist innuendo, all to undermine a candidate he should rather have embraced as an heir to his better self. The former President left the campaign trail diminished and discredited.

The art of graceful losing was never among Bill Clinton's strengths, and it might be said that he is now so compromised a figure that Barack Obama would be better off without his support. This is not, however, how American politics operates, especially not when the presidency is at stake. If Mr Obama cannot unite leading party figures, including former opponents and even former presidents around him, his campaign will be weaker than it should be. Especially after such a divisive primary season, it must be all hands on deck – and that includes not only Mrs Clinton, but her disappointed and ill-tempered husband, too.

Since Mr Obama won the Democrat nomination, Mr Clinton's expressions of support have been distinctly lukewarm and conspicuously few and far between. There have been reports of disdain and rank-pulling on the former President's side. A meeting between the two men, expected this week, is clearly long overdue. If both Clintons can recognise in the Democratic Party nominee many of those same qualities that took the unfancied "man from Hope" to the White House, Barack Obama will be that much closer to having a winning team.