Also, pretty sure the US is in freefall slide into facism already. That slope passed two elections ago.

Originally, that's probably how they started putting those words together in that order.

I'm talking about the idiom of it being applied to anything that isn't a literal slope that's slippery. Like using it to describe that doing thing a will very easily create a situation where another thing is likely to happen.

Eg: smoking weed is a slippery slope to using harder drugs.

(It's not, but I'm sure we've all heard some version of the above before.)