Ditto climate change. It took half a century to evolve the Chicken Little ideology from new ice age to nuclear winter to global warming to finally arrive at climate change, which can fit any and all climatic hiccups and survive all challenges from realists. It has become the ultimate climatic/terrorist weapon.
In the case of sasquatchery, especially with regard to DNA evidence, it will be repeatedly denied as "degraded" or "human" until, by some miracle, somebody plows through all their blockades and proves existence, and then, magically, DNA "discoveries" will allow them to steal the lead and gain some measure of control of the conversation.