We already saw that he didn't destroy democracy or start WW3. You can credit that to "sane people" limiting him but the fact is that what we saw wasn't the Fourth Reich. It was just a shitty Republican president.
If you remember the lesson of that parable, no one believes the chicken when the sky falls and the chicken has no one to blame but himself. You can't keep saying it's the most important election of our lifetimes because we stop believing it.
And maybe the sky falls this time, but it's the chicken's fault that we don't believe it.
That's definitely not why people use Chicken Little as an Aesop. The lesson is that if you lie over and over, people won't believe you when it matters.