Well, Obama’s 2012 campaign was successful. An Obama democrat going over to work for someone who would be a liberal RINO in the US (and running against someone to the left of Bernie Sanders) is not very surprising, this election was a pretty good parallel to Hillary v. Bernie, an experienced woman loved by no one going up against a fringe psychopath and almost losing when she should have won easily.
Certainly May’s campaign was not focused on her attacking her own party. I’m not sure if actually factored into the poor result but some people complained that the campaign was “too negative” and “too American”. Linking Corbyn to the IRA was a significant part of it. Gibmedat types are on the record that they wouldn’t care if Corbyn planned the Manchester attack as long as they got their free goodies.
My impression from everything I’ve read and heard on Sky News, May didn’t personally campaign enough, was robotic when she did (repeating lines like “strong and stable” ad naseum), flubbed her tax plan (this was big, numbers started to tank afterwards), and inspired no one with her response to the terror attacks.
Meanwhile Corbyn did one thing, harped on class warfare to get Labour voters to turn out, and they did.
A ficus plant could’ve run Zero’s recoronation farce in 2012. Having the media and pop culture 99.99% in your corner and (best of all) having a Socialist ringer as an “opponent” in the general election didn’t require any heavy lifting for a campaign manager.