Would a Roy Moore victory mean trouble for other Senate incumbents? Maybe, but these circumstances may not be easily replicated: Roy Moore is much better known than a lot of Senate primary challengers, and the runoff law helps him a lot. “There are those who think that the potential success of Moore’s candidacy could be a jumping off point for insurgent challengers to sitting GOP senators in 2018,” said Geoffrey Skelley, associated editor of Sabato’s Crystal Ball, which is produced at the UVA Center for Politics.