Now it's Ruy Texeira. This is the "the coming democrat majority" guy

I think you're late on Ruy Teixeira. He's been pushing back on the "groups" from the center left for years now.

The climate fanatics that the democrats have cultivated over the years won't stand for it.

I don't think it's even that. Fighting climate change has been one of the central pillars of "Who We Are" for the Democrats for the last twenty years. It was one of the most consequential parts of their agenda, perhaps the largest thing they were fighting for - especially once they fixed health care by enough to make that a back-burner issue. That's why it dominated the BBB/IRA bill so much. It's one of the main things that Democrats wanted to do, if they were elected!

That was always an electorally challenging position to take, given how little voters actually prioritize fighting climate change. But it was still a major pillar - perhaps the biggest pillar - of the platform. Democrats believed that since fighting climate change was (more) popular in other countries that didn't have major fossil fuel company/climate denier problems that once we got past the denial here, their positions would be popular. That shift in popularity didn't happen, and the lack of progress in most other countries has now revealed that support in other places was also only as deep as the measures appeared to be costless (or low-cost).

If the Democrats aren't the party of fighting climate change, what are they going to run on in terms of what they actually want to do with government? Not the goals they want to achieve ("more affordability! less inequality!"), but the actual policies they want to implement? That was their major policy proposal, the one big bill they might want to adopt. What's left of comparable size as The Big Democratic Project if that goes away?