I don't think out matters if Johnson doesn't last the year. As DrB says if Labour had these problems it would be unsurvivable. However with the Tories its grist to the mill or whatever that expression is.
It's been mentioned before on these threads but the way the electorate hold the main parties to completely different standards is fascinating.
Chasms, infighting, stabbing leaders in the back seem to be a positive in the Tory party but are disastrous elsewhere. Even Johnson's martial infidelity, moving into Downing street whilst married to some-one else, is a cause for celebration. Yet Ed Miliband's conventional happy (un)married fidelity was seen as an electoral hurdle.
My theory is that it's do with the grant British sense of class and hierarchy. The Tories are the natural guv'nor and are (falsely) perceived as looking after the serfs. So it's ok for Johnson and colleagues to misbehave in many ways. Internecine strife, ganging up on the leader, secret suppressed reports, dishonesty, infidelity etc. The guv'nors are different to us you see. A lot of them are ' a bit of a lad bless 'em ' - but that's ok.
Yet the other parties are lower down the hierarchy. They are more like the workers who've done well, or middle management or the union rep. So they are held to higher standards.They mustn't get above themselves in any way.
Also the drama, backstabbing, affairs, resignations somehow suits our thirst for soap opera. A steady deliberate, considered, stable option just isn't interesting. Sorry haven't posted much for ages and all I can do is be ultra cynical when I do.