Denouncing three friendly people got the votes for me down to 17. Denouncing seven people, literally everyone I'd met who hadn't formally pledged (totals: 9 pledged to me, 7 pledged to Lukomir, 7 denounced by me, 6 unmet, 1 now disqualified for attempting to assassinate me), got the votes for me down to 15. After the closed recess, it became 18 votes for me. So either Lukomir's pledged electors defected, or people I'd sent burn notices of were still voting for me anyway. :')
Viewing post in Election Strategies (Probably Some Spoilers)
Firing every elector in my cabinet on top of this finally caused an election deadlock! 11 votes for me, 13 for Lukomir, in the first round. Post-recess, 11 votes for me, 15 for Lukomir. No opportunity to cut and run though, just a game over assassination, but without any notified checks. Not sure if there's anything more I can do, or if that's just what happens after an election stalemate.
Strongly implied there is a situation I get to make a choice with "If you lose though, your options are fewer. He did give you a contact method and a promise of help. [...] thought exile was worth it. Will you? Of course, if you succeed, you won't need to make that choice.". Maybe that means I need to find a way to let Lukomir fully win, while still being primed to leave. Maybe I need fewer fully hostile enemies after a stalemate. Maybe it's not possible, and I jumped to conclusions.