Why does it matter how Jeremy Corbyn dresses? Given all the many other things of which one can accuse the leader of the Labour Party, his somewhat scruffy attire is surely one of the least objectionable things about him?
Well, maybe so. But the outrage of Corbyn's supporters over David Cameron's remarks in Parliament during Wednesday's Prime Minister's Questions is still opportunistic, hypocritical opprobrium of the highest order.
Those who say that politics should be about ideas and policies, not about appearance – and that Cameron should be engaging with Corbyn's arguments, rather than making snide remarks about how he dresses – might have a point if they hadn't spent the past six years taking every opportunity to bring up irrelevant personal issues such as which school the Prime Minister went to, along with endless tedious references to the Bullingdon Club, photos of the Prime Minister in formal white tie attire (which are evidently supposed to make us think badly of him, for some reason), and an endless stream of increasingly tiresome 'PigGate' 'jokes' on social media.
The left-wing journalist and commentator Steve Topple wrote in The Independent that Cameron's use of 'personal attacks' against Corbyn proved the Prime Minister had 'lost it'. A quick check through Mr Topple's Twitter account reveals he's not above a few 'personal attacks' himself. It takes a special sort of unscrupulous chain-puller to deploy those kind of tactics against someone for years, then get on your high horse the moment it is returned in kind.
But all of this rather misses the point. Because actually, Corbyn's appearance does matter.
Maybe it doesn't matter very much. Maybe it matters an awful lot less than Trident or Hamas or austerity or housing or anything like that. But it does matter.
Partly, of course, because how you choose to present yourself to the world matters. For anyone. Your clothes, your hair, the way you speak, how you act – all of these things send an instant message to people about what kind of person you are. In politics, where so much of the job is about communicating well, it is foolish to assume these things have no significance. As in any job, if you want people to take you seriously, start by taking yourself seriously – and show up looking like you actually give a damn.
But also because, as Leader of the Opposition, Jeremy Corbyn is lining himself up as a potential next Prime Minister himself. He is asking an electorate to look at him, and choose him to be the person who represents Britain on a global stage. That's not a trivial thing.
Polling has shown us that one of the reasons Labour lost last year's general election is because the public simply didn't see Ed Miliband as a Prime Minister-in-waiting – and nobody could say he wasn't trying. In his ill-fitting, shabby brown jacket that looks like he picked it up in an Oxfam shop, voters don't see Jeremy Corbyn as someone who can go to the United Nations, or the G20, and make people take Great Britain seriously. Facing David Cameron across that dispatch box is an audition to be more than just a backbench MP agitating for fringe causes – to be a statesman. And Corbyn is not coming off well.