Who knows what could scupper Boris Johnson's chances in the General Election?

1)His current majority of 5,000 in Uxbridge is the lowest of any Prime Minister ever.

2)Someone could be in control of a huge vat of sleaze featuring him. Maybe the tap will be opened such that some of it will be let out on several strategically important days. There may even be appropriate video.

3)There is scope for him to say the wrong thing so easily, more so than almost anyone else. Indeed his vocal blunder about Nazanin Zaghari Ratcliffe arguably increased her difficulties. This may get mentioned.