This doesn’t read as if the author is saying the people of the US were the dung pile. The whole election was over-sensationalized by media on both sides, and sank to a lowest common denominator quickly. If anything, the “dung pile” could refer to the fact that we did demean all the Trump voters as belonging to one racist, homophobic pile. It was a biased mess on both sides.
Also, what is wrong with saying that Michelle Obama was a gem in her class and grace? She’s not comparing Michelle to Melania. She’s objectively admiring the behaviour.