The Latin phrase "incidit in scyllam, cupiens vitare charybdim" comes from Greek mythology in the story of Odysseus known also as Ulysses. Scylla and Charybdis were rocks on either side of a narrow inlet. The phrase means trying to avoid Charybdis one founders on Scylla. It represents the idea of having to choose between two evils and has the force of being "on the horns of a dilemma," "between the devil and the deep blue sea."
A Sanders voter withholding a vote from Clinton will run into a Trump presidency, incidit in scyllam, cupiens vitare charybdim!
Interjection indicative of trouble, something wrong
"Jesus fucking Christ on a bicycle! Slow down, but don't stop." Mr. Wednesday in Neil Gaiman's American Gods, Part 2, Chapter 12.