A new litmus test has emerged in the US, which helps weed out the nut-jobs with admirable clarity. It's the charge that President Obama was not, in fact, born in the US but in Kenya. (See this, this and, hilariously, this as examples.)

The evidence for this claim is entirely non-existent. There's more evidence that little green men from another planet have visited us (I am being sarcastic, btw; I was taught a long time ago that sarcasm doesn't work in print).

But despite the fact that the claim is away with the fairies, there are a number of supposedly serious Republicans who make it.

Intriguingly, Slate has done a 'what if': what would happen if it were true?

And the answer, somewhat disappointingly, is...nothing.  

Have a read for yourself here.

In other words: a group of nutcases believe that it's critical to the future of the US to assert as true something which is demonstrably false, in order to achieve nothing.

Genius.