I've heard it argued that, because the Tories are trusted on the economy, they can get away with being bad at it. So George Osborne is more able to get away with making unfunded spending commitments or moving money around and acting like he's found more of it because he is trusted to not behave like that. Labour are still, just about, trusted to be nice. So they are more able get away with being very nasty.
Vicki Kirby isn't just a Labour activist. When she was found to have tweeted a load of anti-semitic bilge she was due to be one of its parliamentary candidates. Within a week of her selection, she was suspended. She joked Jews had "big noses", suggested Hitler was a "Zionist God" and wondered why the Islamic State, the group most like the Nazis of any in the world today, was not attacking the "real oppressors", Israel. The Left relishes a long argument over whether criticising Israel is anti-semitic so I'll limit mine to three words: Oh, come on.
I've not heard any Labour figure suggest Kirby's comments aren't anti-semitic or defend the system that let her be suspended, re-admitted and elected vice-chair of a local party branch. Members have cut up their membership cards over this. MPs spent another fraught Parliamentary Labour Party meeting last night demanding to know how this was allowed to happen. But Labour's crime isn't that it defends this behaviour, it's that it tolerates it.
A party spokesman confirmed Kirby's re-instatement with what was either a tin ear for scandal or a desire to troll those who disagreed with it. The case would be revisited "if new evidence came to light". To reiterate: Kirby looked at a group that beheads aid workers and throws gay people from tall buildings and said Israel was the "real" enemy. Think about that. Kirby might be kicked out like Gerry Downing after this huge outcry. Neither should have been re-admitted in the first place.
It isn't necessarily anti-semitic to tolerate anti-semitism among your friends. But it certainly isn't nice. Labour isn't just risking the support of British Jews, it's risking the perception that it's more decent than the alternative. Cameron has spent a decade trying to convince people they can be decent and vote Tory at the same time. When the Labour machine shrugs off serious allegations with lines about procedure and ongoing investigations, it sounds like it is presuming he will never succeed.
This didn't start with Corbyn - Kirby's case predates his leadership - but that is not an excuse for it to continue under him. I've got no reason to doubt the sincerity of his declaration on Monday that hatred of Jews had "no place" in our society. But his ascent from the obscure Hard Left to leader of one of Britain's two main parties has brought unsavoury elements with it. The Hard Left has a lot of practice at saying reprehensible things because for decades no one was listening.
John McDonnell praised - and that is the only word for it - the work of the IRA in 2003. Anti-semitism allegations within Labour are affecting areas, like university clubs, where the stakes are low. Kirby was due to stand in Woking, where a Labour victory was about as likely as the Martian invasion H. G. Wells imagined while living there. Politics is simpler when you're not seriously expecting to win much - just ask Donald Trump - but now many who spent a long time there on the fringes are coming back to Labour or ascending its power structure. They are far more likely to say outrageous things having gone unscrutinised for so long. Look what Ken Livingstone's wilderness years have done to him.
Douglas Carswell said Ukip had kicked out members with reprehensible views and said "Labour should be held to the same standard". It's strange to think that had to be said. Can you imagine a Tory tweeting "Enoch Powell was right" and then being elected vice chair of a party branch 18 months later? The Right does a better job of kicking out those that stray too far but if you defend Stalin or praise the work of violent thugs, you will find a home somewhere on the fringes of The Left.
Corbyn as Labour leader makes it hard to tell where the fringes are. Some who used to be on the outside are still dancing a merry jig at having "their party back". Did they rise up to take Labour to new heights? Or bring it down to the obscurity they came from? If it's the latter, the Tories won't just be the competent mainstream politicians, they'll be the nice ones too.