Say what you like about Boris Johnson, he can always be relied on to let you down. He is a serial liar who is trusted least by those who know him best. He is also an industrial-strength incompetent whose parliamentary supporters include just one of the ministers who served with him during his rackety two years as foreign secretary. Then there is the hefty back catalogue of offensive remarks and a private life that would stagger David Lloyd George or the Duke of Wellington. Rory Stewart, one of the other competitors in the leadership race, has even suggested that Mr Johnson isn’t fit to give proper instructions to the commanders of Britain’s nuclear submarines. Not safe with the deterrent is an accusation that Tories sometimes level at Labour leaders, but I’ve never before heard it hurled at a putative Conservative leader by a fellow blue.

This is a short summary of reasons that other Tories supply to explain why prime minister Johnson is a reckless idea. You hear them often from Tories who are nevertheless voting to install him at Number 10. Written off as a busted flush by many colleagues just a few months ago, the boy who once talked about becoming “king of the world” is closer than ever to capturing the premiership of Britain. If all is not forgiven, it is at least being temporarily forgotten in a collective outbreak of double-think and blind desperation.
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He wouldn’t be winning without the willingness of many Tory MPs to suspend their disbelief. They are working terrifically hard to persuade themselves that they will get the version of Boris Johnson that they like without any of the features that repel them. So he’s getting the backing of Brexit ultras who claim he’ll deliver their version of the enterprise. He’s also garnered support from one-nation-type Tories who are telling themselves that the former mayor of London is really a liberal centrist. This coalition is riddled with ideological contradictions and he has already made promises that he simply won’t be able to fulfil. Don’t imagine that Tory MPs aren’t aware of this. The sentient ones are perfectly conscious of it as they equally know that he is a wild gamble that could go disastrously wrong for both their party and their country.

Fear is the key to understanding why, fear most of all of Nigel Farage. This is the single most important factor propelling Boris Johnson towards Number 10. The leader of the Brexit party is not on the ballot paper, but he is the most influential personality in this contest. He is a giant magnet attracting clouds of iron filings in the direction of the former foreign secretary. By far and away his biggest-selling proposition to Tory MPs terrified of losing their seats is that he is the only one of them with the force of personality to stand any chance of suffocating the Brexit party and defeating Labour.

https://www.theguardian.com/commentisfree/2019/jun/16/dirty-secrets-of-boris-johnsons-seduction-of-conservative-mps