Yes, I've seen that slide. In fact, it was exactly what I had in mind when I said to pytester below that "Barnier has been crystal clear about what is required of the UK and what the options are". Certainly you are right about what has been the Tory negotiating strategy.

I meant, however, that she could have attempted to sell it to the hardliners in her party or, more likely, cross-party as described below. None of the red lines were inevitable, because no one knows why Leave won. Some say immigration, some say sovereignty, ECJ, payments that could "fund our NHS", and myriad other things. Some in Labour are even said to have supported it to get around state aid rules.

So there was a fundamental lack of clarity what the referendum had actually meant shortly after it passed. That was TM's window of opportunity to show some leadership and choose an interpretation of the referendum that could command majority support.

If she had presented a soft Brexit agreement to the house, yes, she would have thrown the DUP and ERG under the bus, but she also would have put Labour, LD, etc into an extremely difficult position. At the time, they all said "we should respect the referendum". If they had rejected a soft WA the blame would be all on them instead of, as it is now, on the Tories. She would have faced accusations of being a closet Remainer, but she got that anyway.

I am convinced everyone hates the DUP and very few like the ERG. Instead of tossing them, the Tories toss Ken Clarke and Nick Soames? Sounds like a bad plan.