This meme seems to be cropping up in various think pieces around the world; Matthew Yglesias points out the obvious flaw:
It seems to me that any talk of the end of conservatism is not only premature, but fundamentally misguided. It’s in the nature of things that politicians and intellectuals whose ideas tend toward the preservation of existing wealth and privilege are going to manage to find money and institutions to support them. The right sequence of events could push such a movement out of power for a while, but any incumbent regime is bound to be tripped up by bad luck or mistakes soon enough. And when it does, people turn to the alternative.
I’d also add that the train wreck that is the current US Republican Party isn’t even about the collapse of a conservative party – its about a conservative party transforming itself into a christian nationalist party and becoming intensely unpopular in the process.
It’s also worth bearing in mind that political movements rebuild fast these days; after the epic failure of the Kerry campaign in 2004 the democrats were a spent force – look at them now.