Complex sentence: It has been argued that Gladstone mishandling the Bradlaugh affair, which gave the opposition a religious cudgel they used for years and that, as a result, the second term was not nearly as successful as the first.
Split into simpler sentences: It has been argued that Gladstone mishandling the Bradlaugh affair, which gave the opposition a religious cudgel they used for years. As a consequence the second term was not nearly as successful as the first.