The old legal maxim, bad cases make bad laws, applies equally to political leadership. Thus, the question (who would be the more disastrous prime minister, Jeremy Corbyn or Boris Johnson?) is not worthy of serious consideration, for the obvious answer is, both.
Corbyn, if we imagine him in the nation’s highest office, would at least be sincere in what he tried to achieve. The same could not be said of Johnson, whose opinions on anything on any given day correspond to his estimate of which view at which moment is likely to command most support among Tory voters.
Corbyn’s Downing Street office would be adorned by busts of Keir Hardie and Karl Marx.