I am not suggesting that we make this the dividing line but that we exclude the new populist right from power have the dividing line between the current centrist and progressive parties. I do sometimes wonder if there was the same debate in Poland and Hungary.
The problem is that you don't get to choose where the dividing line is. Once you've lined up a coalition of unpopular middle-management types against a single popular party, that's where the dividing line is, whether you like it or not. Subsequently almost anything the single popular party does becomes the Authentic Will of the People just by virtue of the fact that people actually voted for that party, and the Suits are trying to thwart them.
Beyond that I honestly don't think that you can "exclude the new populist right from power" with what will almost certainly be seen as electoral shenanigans without very serious consequences, not when that populist right *is actually popular* - the most popular single* political identity in the country, in fact, and well-funded to boot, with a massive mainstream media operation shaping and maintaining it. The populist right in this country is also not at all new: it's dominated British politics since Thatcher co-opted Powellism and it has a great deal of establishment support. It's unthinkable that such a force would *allow* itself to be excluded from power in the way you suggest, but if it did happen then things could *really* get nasty.
Which was also the view when Trump came along, not least on PFM, and what started me on this change of view.
On the coalition of arseholes I think the parallels with Trump can be overstated. My impression was that when Trump hit, the whole liberal political-media establishment came together to fight back and resist the normalisation of that kind of politics. That is the exact opposite to what happened here: our *liberal* media, never mind the right wing press, have been normalising Faragism for decades, and when it reached its climax - proroguing, rock hard Brexit, an election campaign built on pure lies - our progressives, in the media and in politics, came together *to make sure it succeeded*, as the acceptable cost of excluding the left from power. I'm not complaining, I'm just pointing to that as a symptom of our really very messed up politics: "Trumpism" is embedded in the British establishment in a way it isn't in the States' and our establishment progressives are *exceptionally* self-serving, obtuse and compromised, with the result that dividing lines are much harder to draw.
As I say I'm all in favour of constitutional reform but it can't be imposed from above and it's not going to fix anything by itself, even in the short term. If you want to beat the right there just are no shortcuts to developing a political programme that will attract popular support.