Errr, it's a lot more complicated than that. People in the US have been buying up ammo at > 10 billion (thousand million) rounds/year rates for more than a decade now (US civilian production is > 12 billion/year, which doesn't count imports and not, I think, surplus and seconds from Lake City production), and I haven't noticed big movements before elections (after, for sure).
The people behind the prepping industry are just affiliate marketers for the most part.