Brendhan from Florida is not happy with Barack Obama. “What the heck is going on?” he asks the senator in a blog entry on the official web portal of the Democratic presidential campaign. “I keep having to endure one disappointment after another . . . When are you going to stand up and [show] some spine again?”

A month after Mr Obama sealed the Democratic nomination, his army of online supporters is showing signs of division. Bloggers have inundated the portal – my.barackobama.com – with protests about his shift to the centre.