If the US government really had alien bodies, then the US president would know about it.
If the US president knew about it, then Trump would know about it.
If Trump knew about it, he would have told everyone, bragged about it, kept boxes of documents about it at Mar-A-Lago, etc. There would be a ketchup stained original photograph of an alien autopsy on the floor of his bathroom.
Since we haven't heard him brag about having seen a photo of an alien, we know that he hasn't seen one.
