Flying off the shitpile
When a lowlife person or group entity of people abandons one particular foul interest or behavior for one even worse, such as flies would abandon a mere pile of shit for a foul-smelling, bloated and rotted carcass.
"All of today's Republicans adore Donald Trump and want to become more and more like him every day, so they sure as hell ain't gonna be flying off the shitpile just for a moderate conservative like you!"