Complex sentence: Question by question, Hutchinson effectively stonewalled him in her responses, and Winthrop was unable to find a way to convert her known membership in a seditious faction into a convictable offence.
Split into simpler sentences: Question by question, Hutchinson effectively stonewalled him in her responses. The floundering Winthrop was unable to find a way to convert Hutchinson's known membership in a seditious faction into a convictable offence.