Appearances notwithstanding, we are not governed by imbeciles. Our problem is that we are governed by unscrupulous politicians who see imbecility as the way to the voter’s heart. Step forward Theresa May, the current Miss Whiplash of the Tory front bench, who wants a solemn commitment in the next Tory Manifesto to expel all foreign graduate students after they graduate and make them apply from abroad for visas to work in the UK. Yes, you read that correctly. She wants to force bright young foreigners, who come to do research degrees in the UK because we have some great universities, to leave the moment they become available for work in our knowledge-based industries.

Here’s how James Dyson, the entrepreneur and inventor puts it:

Train ’em up. Kick ’em out. It’s a bit shortsighted, isn’t it? A short-term vote winner that leads to long-term economic decline. Of course the government needs to be seen to be “doing something”. But postgraduate research in particular leads to exportable, patentable technology. Binning foreign postgraduates is, I suppose, a quick fix. But quick fixes don’t build long-term futures. And that’s exactly what many researchers are doing.

Bright sparks are drawn to the UK for good reason – our universities are among the best in the world. Particularly for science and engineering. Yet the Home Office wants to say cheerio to these sharp minds as soon as their mortarboards land on college lawns. The moment research is finished students are forced back to their homelands, from where the home secretary is happy to allow them to apply for jobs in Britain. Not exactly motivating. Not exactly practical. This is an abrupt departure from an equally unworkable idea that after their research they have two months to be employed, otherwise they are ejected. No wonder fewer than 10% bother to try to stay.

Our borders must remain open to the world’s best. Give them our knowledge, allow them to develop their own and permit them to apply it on our shores. Their ideas and inventiveness will create technology to export around the world.

The interesting question, of course, is why Miss Whiplash thinks that her daft policy idea will be a vote-winner in a closely-fought election? The logical inference is that she thinks that voters are imbeciles. In which case she is following in the footsteps of one of her heroes, Winston Churchill, who famously observed that “the best argument against democracy is five minutes’ conversation with the average voter”.

Sigh.