Complex sentence: Thereafter, Vaughan Davies was comfortably returned at each election but the vitality of the Liberal Association was in serious decline, and by 1914 it was heavily dependent on Vaughan Davies's role as treasurer to keep it going.
Split into simpler sentences: Thereafter, Vaughan Davies was comfortably returned at each election but the vitality of the Liberal Association was in serious decline. By 1914 the Association was heavily dependent on Vaughan Davies's role as treasurer to keep it going.