Why are TRUMP NFTs selling for million dollars?

They are being offered at that price (999ETH), not necessarily sold. The creator has not sold a single item yet:

https://opensea.io/BullionArts/deals

https://opensea.io/collection/art-by-the-bullish-moves?searc...

Because all NFTs and altcoins are pump and dump scams.

Legalized bribery would be my guess.