Archie Bland: In Topeka or Harare, a sense of humour is a must

There are a lot of reasons it was stupid of Kansas governor Sam Brownback's staff to get their knickers in a twist when a teenager tweeted that their boss "sucked", but chief among them is surely this: Mr Brownback now looks slightly more like Robert Mugabe.

Being vulnerable to such a comparison is never great news for anyone looking to project himself as a vision of shining-eyed, democratic nobility. But a sense of humour failure in Topeka is really no less ridiculous than one in Harare, and both serve as a reminder of the same point, which should be engraved in stone for powerful people everywhere: nothing makes you look so absurd, so undercuts your authority, as failing to see the funny side.

In Harare yesterday, the sour-faced culprits were the members of a militant youth group who demanded a boycott of South African Nando's in retaliation for an ad featuring their beloved old bastard alongside his fallen despotic comrades. It wasn't high art, exactly, but it included a fine segment where Mr Mugabe and the late Colonel Gaddafi sprayed each other with water pistols. Also, it was for Nando's, and if these pompous so-and-sos don't realise most people like Nando's more than they do Robert Mugabe, they need to commission a few more focus groups.

The same advice could be applied to Mr Brownback's political operatives, who managed to create a calamitous media firestorm where no threat of one existed by taking exception to an 18-year-old's throwaway tweet and reporting it to her school. Besides anything else, the girl in question, Emma Sullivan, was displaying exactly the civic engagement we're supposed to nurture in young people; so when her head teacher demanded she write an apology, and Emma refused, it didn't take political antennae of Alastair Campbell-like acuity to divine who would come out of it better. Sure enough, Brownback ended up apologising on behalf of his advisers. Ms Sullivan, meanwhile, got an extra 15,000 Twitter followers – quite an increase on her original 60. As yet, no-one in the Mugabe camp has withdrawn their foolhardy demand for a boycott.

Presumably they are less concerned about the impact on the polls than their American counterparts. All the same, as they jump up and down ineffectively, and the ad mocking their standard-bearer sweeps past half a million views on YouTube, they may want to consider: while they reinforce the sense that Mugabe is an inhuman old sod, everyone else is eating delicious spicy chicken. And the rest of us are having a much better time.