We’ve heard the joke. The one said by comedian Allan Billison at the union function attended by senior Labor figures like Wayne Swan and Julia Gillard (although she’d left by the time the joke was said). It offends not in its s-xism, and not in its language, which does not match the gutter talk of the Slipper texts. It’s not funny. In the slightest. We’re not going to repeat it, and nor has any other media outlet. It’s hurtful to those involved, and may be defamatory.

Swan was on ABC Radio this morning. He said the joke was “inappropriate” and he had told the union so. When did he call them? “The next morning.” When the next morning? “Early.” Before journalists found out about it? “Well before.” Why didn’t he leave the function? “I was the guest speaker.” What does this say about his judgment? “I in retrospect should have conveyed my opinion on the night.” Has the government set a new benchmark it can’t reach? “No, I don’t believe so.”

Actually, yes. And nobody could reach that benchmark.

The Coalition line is Swan and his colleagues should have left. Or perhaps charged the stage, tackled the comedian and demanded an apology while immediately expressing their own regret for, well, breathing the same air as the comedian. It’s a witch-hunt demanding ridiculous standards of behaviour. And it’s exactly the same charge Labor made of the Coalition frontbenchers who just happened to be in the same room as a vile shock jock mouthing off about the Prime Minister.

Labor brought this onto itself.

It’s possible to separate a worthy debate on s-xism and aggressive public debate from the farcical way some MPs want to play it on the ground. Gillard’s parliamentary attack on Tony Abbott in the name of misogyny was a powerful moment. Days later we’re stuck talking about guilt by the vaguest of associations.

Politics went to strange places this week. It ends in the strangest.