1. So here’s where we are: Johnson’s authority is made of balsa. He depends upon the taxpayer-purchased votes of the DUP and the support of his own parliamentary party, many of whom want much more than the backstop excised from May’s deal....

2. He is only in office at all because of the decision taken by the tiny selectorate of Tory members. His mandate is constitutionally sound but politically frangible. BUT...