Orthodox satire does not and cannot work as it used to do. The balance has changed. The comedians are often more influential, wealthy, adored and famous than the largely unknown yet still-loathed politicians they mock. So I have become the first political columnist to perform a one-man show, taking to the stage for five nights in London before heading for the Edinburgh Festival. I am joined, sort of, by the likes of Cameron, Osborne, Miliband, Blair, Brown and others.