There is always the moment. The point at which the bough breaks, the tide turns, the die is cast. For Theresa May, it might have been Monday, when she cancelled the vote on her EU withdrawal agreement, which resulted in enough letters from Conservative MPs to trigger a confidence vote in her leadership. . https://www.heraldscotland.com/news/17294200.alison-rowat-prime-minister-has-won-the-battle-but-is-the-war-lost/